Chapter 30

Against Classical Divine Simplicity and Strong Immutability

Why They Must Go

Introduction: The Foundations Beneath the Foundation

Throughout this book I have been building a case for a God who is genuinely temporal — a God who acts in time, who responds in real moments, who meets us where we are. Along the way, I have had to answer many objections. Some have come from Scripture. Some have come from physics. Some have come from the long tradition of Christian thought. But under all of those objections, holding them up like pillars beneath a great cathedral, sit two doctrines that simply must be addressed head-on. Those doctrines are classical divine simplicity and strong immutability. In this chapter I want to argue, carefully and with respect for those who disagree, that these two doctrines — at least in their strict classical forms — must go. They cannot stand. And when they fall, the case for a timeless, frozen, unresponsive God falls with them.¹

Let me explain why this chapter matters so much for the larger argument. If you ask a thoughtful defender of divine timelessness why God must be outside of time, you will usually be given one of two answers. The first answer is: "Because God is absolutely simple." The second answer is: "Because God is absolutely immutable — He cannot change in any way at all." These are not two separate arguments. They are two sides of the same coin, and they work together with a third doctrine, divine impassibility (the claim that God cannot be affected emotionally by anything outside Himself), to form what R. T. Mullins rightly calls "a very tight package" of classical divine attributes.² If you pull at one of the threads in this package, the whole thing starts to unravel. Mullins puts it bluntly: "These divine attributes are simplicity, immutability, and impassibility. As one shall see throughout the argument of this book, these divine attributes form a very tight package in Christian thinking. Any assessment of divine timelessness must involve an assessment of these attributes as well."³

So what are we actually saying in this chapter? We are saying three things. First, the doctrine of strict divine simplicity (the view that all of God's attributes are identical to each other and to God's essence, with no real distinctions in God at all) is philosophically incoherent, theologically ruinous for orthodox Christianity, and scripturally unsupported. Second, the doctrine of strong immutability (the view that God cannot change in any respect whatsoever, not even in His relations to creatures) fails on every single test a Christian doctrine ought to pass: biblical fit, philosophical coherence, theological usefulness, and pastoral credibility. Third — and this is what makes the chapter truly decisive — these two classical doctrines, far from being independent supports for timelessness, are really the same argument wearing two different costumes. Both doctrines rule out succession in God. Both doctrines rule out genuine relation to a changing world. Both doctrines, when taken strictly, make God into something less like the Father of Jesus Christ and more like a Platonic abstract object. If I can show that simplicity and immutability must be softened, then the last real arguments for divine timelessness collapse.

I want to be very careful about one thing before we go further. I am not saying that classical theologians were foolish. Far from it. Augustine, Anselm, and Thomas Aquinas were some of the brightest minds the church has ever produced. They were working within a particular metaphysical framework — one heavily shaped by Plato, Aristotle, and Neoplatonism — and given that framework, their conclusions were sometimes very reasonable. What I am saying is that the framework itself was flawed in important ways, and that when we look back at what the Bible actually teaches about God, and when we think carefully about what is required for the Christian story to be true, we find that the classical framework cannot quite hold the weight of Christian orthodoxy. It bends in places it should not bend. And it breaks right where the gospel lives — at creation, at the incarnation, at the cross, at the resurrection, at prayer.⁴

With that said, let us begin. We will proceed in six main steps. First, we will look at why these two doctrines are the philosophical foundations of timelessness — why, if they stand, timelessness stands, and why, if they fall, timelessness falls with them. Second, we will define strict simplicity carefully and present the classical arguments for it fairly. Third, we will critique it. Fourth, we will do the same for strong immutability. Fifth, we will look at what is worth preserving in each doctrine and articulate positive alternatives. Finally, we will step back and see how simplicity, immutability, impassibility, and timelessness form a single interlocking package — a package that, once we reject one piece, must be reassembled on very different foundations.

1. Why These Doctrines Are the Foundation of Timelessness

Let me begin with what might seem like a surprising claim: the doctrine of divine timelessness does not actually stand on its own. It has almost never been defended, in the history of Christian thought, as a stand-alone thesis. Instead, it has been defended as a consequence of two deeper and more fundamental doctrines: simplicity and immutability. If you trace the classical arguments back to their roots, you will almost always find that the argument for timelessness runs something like this: God is simple; whatever is simple cannot have before-and-after in its life; therefore God cannot be temporal. Or this: God is absolutely immutable; whatever is temporal undergoes change; therefore God cannot be temporal. The doctrine of timelessness is, in the classical tradition, a derived doctrine. Pull its foundations out from under it and it has nothing to rest on.⁵

William Lane Craig, for all his disagreements with the author of this book on some matters, has put this point as clearly as anyone. In Time and Eternity he lays out the classical argument for timelessness in formal terms. The argument takes this shape: (1) God is simple, or (1′) God is immutable. Then (2) If God is simple or immutable, then He is not temporal. Therefore (3) God is not temporal. And since temporality and timelessness are contradictories, (4) God is timeless.⁶ This is a valid argument. The only question is whether the premises are true. And Craig, being a careful philosopher, goes right to the heart of the matter: "while we may freely admit that a simple or immutable God must be timeless, we have even less reason to think God simple or immutable than to think Him timeless and so can hardly infer that He is timeless on the basis of those doctrines."⁷

That is a devastating observation, and I want the reader to sit with it for a moment. The classical argument for divine timelessness runs: "God is simple (or immutable); simplicity (or immutability) entails timelessness; therefore God is timeless." But if we have more reason to doubt that God is strictly simple and strongly immutable than we have reason to doubt that God is timeless, then the argument has gone backwards. We would be trying, in Craig's memorable phrase, to "prove the obvious via the less obvious."⁸ That is never a wise philosophical strategy. You do not prove things that might be doubted by appealing to things that are even more doubtful. And yet that is exactly what the traditional argument for divine timelessness asks us to do.

Why does this matter so much for the argument of this book? Because it means we do not need to knock down divine timelessness with a hammer and then build something else in its place. All we really need to do is show that simplicity and immutability, in their classical strict forms, are themselves unstable. If the foundation gives way, the building comes down without any extra pushing on our part. And that is precisely what I intend to show in the pages that follow. When the strict doctrines of simplicity and immutability go, timelessness goes with them — and what we are left with is a view of God that is much closer to the God of Scripture: a God who genuinely acts, genuinely responds, genuinely loves, and genuinely walks with His people through time.

2. What Is Classical Divine Simplicity? — A Fair Hearing

Before we can critique something, we must first understand it. So let me try to lay out the classical doctrine of divine simplicity as fairly as I can, drawing on its most serious defenders both past and present. I want the reader to feel the force of the doctrine, not just its difficulties.

At its heart, divine simplicity is a claim about what kind of being God is. The claim is that God has no parts. Now, when most modern people hear the phrase "no parts," they think: well, of course, God is not a physical being; He does not have arms or legs or molecules. That is true, but it is not nearly enough. The classical doctrine is far more radical. Peter Lombard's definition is a good place to start: "The same substance alone is properly and truly simple in which there is no diversity or change or multiplicity of parts, or accidents, or of any other forms."⁹ Lombard is ruling out any kind of part or division whatsoever — physical parts, metaphysical parts, temporal parts, even conceptual distinctions. God, on this view, is an "absolutely undifferentiated unity," as Craig puts it.¹⁰

What does this mean in practice? Mullins, drawing on Augustine, Anselm, Lombard, and Aquinas, breaks classical simplicity down into several specific claims. Let me restate them in plain English. First, God does not have physical parts — no body, no spatial extension. Second, God does not have metaphysical parts — there is no distinction in God between essence and existence, between substance and properties, between one attribute and another. Third, God does not have temporal parts — God's life cannot be divided, not even conceptually, into a "before" and an "after." Fourth, God does not possess any properties at all; properties, in the strict sense, belong to creatures, not to God. Fifth, God is His attributes: God does not have love; God is love, and not just in the beautiful sense John intended in 1 John 4:8, but in a strict, metaphysical, identity-claim sense. And sixth, God is pure act (actus purus) — God has no potentiality, no capacity to be other than exactly what He is right now.¹¹

Augustine stated the identity-of-attributes claim about as clearly as anyone. In The Trinity, he writes that whether you say God is "wise, powerful, living, understanding, or beautiful... the same thing is being said."¹² In another passage of the same work, Augustine insists: "it is the same thing for God to be as to be powerful or just or wise or anything else that can be said about his simple multiplicity or multiple simplicity."¹³ Thomas Aquinas followed Augustine on this and developed it further: God is identical to His act of existence, and all the "manifold actions ascribed to God, as intelligence, volition, the production of things, and the like, are not so many different things, since each of these actions in God is His own very being."¹⁴

Now, why would any thoughtful Christian theologian want to say all of that? The defender of classical simplicity has several serious reasons, and I want to state them fairly.

The first reason is theological. The classical theologian wants to protect the aseity of God — the doctrine that God depends on nothing outside of Himself for His existence or for anything that He is. If God had distinct attributes, the worry goes, then God would depend on those attributes to be God. His goodness would be something He participates in, the way a creature participates in some abstract form of goodness. But God is not supposed to participate in anything; He is the source of everything. So, the classical theologian concludes, God must be His goodness, not have it. Katherin Rogers, a contemporary defender of strict simplicity, puts it this way: "With God we do not hypothesize any unity underlying the diversity because there is no diversity."¹⁵

The second reason is metaphysical. In classical metaphysics, any being that has parts depends on those parts for its existence. A being with parts is, in some sense, held together; and whatever is held together can, in principle, come apart. But God cannot come apart. God is necessary. Therefore God must have no parts. This is Anselm's way of thinking in the Proslogion, where he argues that "whatever is made up of parts is not absolutely one, but in a sense many and other than itself, and it can be broken up either actually or by the mind — all of which things are foreign to" God.¹⁶

The third reason is the desire for divine perfection. On classical thinking, to be a perfect being is to lack nothing and to have no potential. A being with unrealized potential is, in some small sense, incomplete. God, who is the most perfect being possible, must therefore have no potential at all. He must be pure actuality. But if God has distinct attributes, or parts, or if He can change, then He has potential — the potential to be different in some respect. Therefore, the classical argument goes, God must be simple and unchanging.¹⁷

These are real and thoughtful reasons. I do not want to dismiss them. But I also do not think they are enough, and I want to show in the next section why I believe strict simplicity ultimately fails as a Christian doctrine.

3. The Case Against Strict Divine Simplicity

Let me now offer four main objections to the strict classical doctrine of divine simplicity. These objections are philosophical, theological, scriptural, and pastoral, and together I think they are overwhelming.

3.1 The Love-Is-Wrath Problem: Identity of Attributes Collapses Into Nonsense

The first and most famous objection comes from Alvin Plantinga, though others have made it as well. If all of God's attributes are truly identical to each other — not just mutually entailing, not just inseparable, but identical — then it follows that God's love is identical to God's wrath. God's mercy is identical to God's justice. God's knowledge is identical to His power. And each of these, in turn, is identical to God Himself. But this is just barely coherent, if it is coherent at all.¹⁸

Plantinga pushed the objection even further: if all of God's properties are identical, then there is really only one divine property. And if God is identical to this one property, then God is a property. But properties, as traditionally understood, cannot think, cannot act, cannot love. So if God is a property, then God is not anything like the Christian God.¹⁹ Now, classical defenders of simplicity like Rogers have tried to sidestep this objection by saying that the simple God does not even have properties. There is no property that God is identical to; there is only the simple divine substance.²⁰ That is a clever move. But it actually makes things worse, not better.

Here is why. If we say that God does not have properties — if we say that everything we call a divine "attribute" is really just one undifferentiated thing — then we cannot say anything meaningful about God at all. Consider: when I say "God is love," I mean something. I mean that God has a certain disposition toward His creatures. I mean that His will is directed toward their good. I mean that He cares for them, acts for them, gives Himself for them. When I say "God is just," I mean something different. I mean that God gives each creature its due. I mean that He punishes wickedness and rewards righteousness. But if these two statements are saying the same thing, then I am not really saying two things at all. I am saying one thing twice, using different words to no effect. Language about God collapses into empty tautology.²¹

Craig makes the same point when he notes that strict simplicity implies God "does not possess even distinct attributes. In some mysterious way His omnipotence is His goodness, for example."²² That word "mysterious" is doing a lot of work here. When classical simplicity runs into the wall of incoherence, its defenders often retreat to mystery. But mystery is not the same as incoherence. A real mystery is something we know to be true but cannot fully understand — like the Trinity, or the hypostatic union. An incoherence is something that simply makes no sense as stated. To say that love is identical to wrath, in the same respect and at the same time, is not a mystery. It is a contradiction.²³

3.2 The Theological Non-Starter Problem: Simplicity Destroys Theology

Here is a second problem. If strict simplicity is true, then Christian theology becomes impossible to practice. Mullins has put this objection forcefully, and I think it is devastating.

Every serious work of Christian theology involves making distinctions in God. We distinguish between the three Persons of the Trinity. We distinguish between God's natural attributes (like omnipotence) and His moral attributes (like goodness). We distinguish between God's primary and secondary willing, between what He positively wills and what He permits, between His antecedent will (what He wants considered in isolation) and His consequent will (what He decides given all the circumstances). Without such distinctions, we cannot even begin to solve the problem of evil, or understand the atonement, or talk coherently about the Trinity. Theology requires making careful distinctions.²⁴

But strict simplicity says that no distinctions in God — not even conceptual ones — correspond to anything real in God. Anselm is crystal clear on this: "what either actually or conceptually has parts can be divided into parts, and this is altogether foreign to God."²⁵ Not even conceptual distinctions apply to the simple God. They exist, at most, in our minds. But if that is the case, then every careful distinction the theologian makes — every careful labor of systematic reflection — turns out to be a distinction about our concept of God, not about God Himself. Mullins observes: "After the theologian has spent dozens of pages making careful distinctions in God to remove the paradox she must admit that her distinctions exist in her mind only. They do not apply to God at all because there is nothing in God that could ground the conceptual distinctions... In other words, she has just committed all of her work to the flames."²⁶

This cannot be right. If Christian theology is even possible, then real distinctions in God must be possible. The Father really is not the Son. The Son really is not the Spirit. God's mercy really is distinguishable from His justice, even if they flow from the same holy nature. If we say that none of these distinctions pick out anything real in God, we are not preserving God's transcendence — we are abandoning the ability to say anything meaningful about Him at all. As Mullins puts it, "It would seem that divine simplicity makes Christian theology a non-starter."²⁷

3.3 The Trinity Problem: Simplicity Endangers Orthodoxy

The third objection is perhaps the most serious, because it concerns the most central of Christian doctrines: the Trinity. If God is strictly simple — if there can be no real distinctions in God — how can there be three real Persons in God?

Craig puts the worry clearly: a strictly simple God "is not really composed of three distinct persons, a claim notoriously difficult to reconcile with the doctrine of the Trinity."²⁸ If the Father and the Son and the Spirit are all identical to the divine essence, and the divine essence is identical to itself, then the Father just is the Son and the Son just is the Spirit. But that is Modalism — the ancient heresy that says the three "persons" are just three modes or masks of one and the same divine being. Orthodox Christianity has always insisted that the three are really distinct Persons, even though they share one divine essence.²⁹

Classical theologians, of course, were aware of this difficulty. They tried various sophisticated moves to resolve it. They spoke of the "relations of origin" (the Father begets, the Son is begotten, the Spirit proceeds) as being somehow real distinctions in God without threatening simplicity. They developed the concept of "subsistent relations" — relations that are identical to the divine essence itself but also distinguish the Persons. These moves are ingenious, but they are also strained. Mullins notes that Jewish and Muslim critics of the Trinity have long pointed out that the doctrine of divine simplicity, as classical Christian theologians themselves understood it, does not sit easily with the tripersonal nature of the Christian God.³⁰

The honest response, I believe, is to admit that strict simplicity and Trinitarianism are in genuine tension. If we must choose — and I believe the evidence of Scripture forces us to choose — we must choose Trinitarianism. The Father, Son, and Holy Spirit are really three. They are not three masks of one; they are three Persons who share one divine nature. And that requires some form of real distinction in God. It requires, in other words, a rejection of strict simplicity in its fullest classical form.³¹

3.4 The No-Real-Relations Problem: Simplicity Makes Creation Impossible

A fourth objection concerns creation. Classical simplicity, combined with classical timelessness and immutability, entails the doctrine of no real relations: God is not really related to the world. God is said to sustain the world, but the relation is only "really" in the world's direction — the world is really related to God, but God is not really related to the world. This is not a strange extrapolation; it is a standard classical claim.³²

Why would anyone say such a thing? Because if God were really related to the world, that relation would be a real feature of God. And real features of God are, on strict simplicity, identical to God. So God's being related to the world would be identical to God's essence. But God's essence is necessary and unchanging. So the relation to the world would be necessary — meaning God could not have failed to create, and the world must be necessary too. To avoid this, classical theologians said that God is not really related to the world at all.

Craig rightly objects: "God's sustaining the world is a causal relation rooted in the active power and intrinsic properties of God as First Cause. It is therefore not at all analogous to the passive relation is envied by. Thus, to say that the world is really related to God by the relation is sustained by, but that God is not really related to the world by the relation is sustaining seems unintelligible. It is to say that one can have real effects without a real cause — which seems self-contradictory or incomprehensible."³³

The no-real-relations doctrine is not a quirky side effect of classical simplicity; it is its direct consequence. And it contradicts the entire Christian story. If God is not really related to the world, then He is not really its Creator, not really its Lord, not really its Redeemer. These titles, on strict classical simplicity, reflect facts about us, not about God. Augustine himself admitted this, saying that accidental predicates like "Creator" and "Lord" "only befall us and not God."³⁴ Mullins observes that this extreme conclusion was consistently drawn by Augustine, Boethius, Lombard, and Aquinas: "classical theologians held that we can refer to God, but that we must realize that our accidental predicates only befall us and not God."³⁵ But this is not what the Bible teaches. The Bible teaches that God really is the Creator, really is the Redeemer, really is the Judge of all. These are not illusions created by our way of speaking. They reflect realities about God Himself — realities that strict simplicity cannot accommodate.

3.5 The Scriptural Silence on Strict Simplicity

One final point on simplicity: where, in the Bible, is the doctrine of strict divine simplicity taught? The honest answer is: nowhere. Scripture teaches that God is holy. Scripture teaches that God is one (Deut. 6:4). Scripture teaches that there is no God beside Him (Isa. 45:5). Scripture teaches that God is not a man, that He does not lie, that His character is trustworthy. But Scripture never teaches the specific metaphysical claim that all of God's attributes are identical to each other, or that God has no potentiality, or that God cannot undergo any extrinsic change. These are claims from Greek metaphysics, especially Platonism and Aristotelianism, that were read into the biblical text by theologians who assumed their truth and then found supporting hints in Scripture.³⁶

Craig notes pointedly that "the doctrines of divine simplicity and immutability as explained above find absolutely no support in Scripture."³⁷ What we find instead is a God who acts, who speaks, who chooses, who responds, who loves — a God whose inner life is rich and varied, not a monolithic identity. The biblical God is one, but He is not strictly simple.

4. What Is Strong Immutability? — A Fair Hearing

Now let us turn to the doctrine of strong immutability. As with simplicity, I want to begin by stating it fairly.

Strong immutability, in its classical form, is the claim that God cannot change in any respect whatsoever. Not just that God does not change — that would be the weaker claim — but that God cannot change. It is metaphysically impossible for God to undergo any alteration at all. As Mullins summarizes, classical immutability "states that God does not undergo any kind of change."³⁸ And crucially, this applies to both intrinsic change (changes in God's essential nature) and extrinsic change (changes in God's relations to creatures, sometimes called "Cambridge changes").³⁹

Peter Lombard, whose Sentences shaped much of the medieval discussion, defined immutability in just these strong terms: "a being undergoes temporal succession by changing either intrinsically or extrinsically. Hence, God is immutable in that God does not and cannot undergo any intrinsic or extrinsic change."⁴⁰ Paul Helm, a leading contemporary defender of classical theism, insists on exactly this point: the denial of extrinsic change is "crucial" for the classical view, because any extrinsic change would generate a before-and-after relation that locates God in time.⁴¹ Craig and Moreland, though they reject classical theism themselves, agree that this is the classical understanding: "Divine timelessness or divine simplicity would require that God undergo neither intrinsic nor extrinsic change. For in either case a relation of before and after would be generated by such changes which would serve to locate God temporally with respect to those changes. Thus God would have to be incapable of even the slightest alteration."⁴²

Why do classical theologians affirm such a strong doctrine? There are several interlocking reasons.

The first reason is the Platonic assumption about value. As Mullins explains, the classical tradition assumes that there are no value-neutral changes: all change is either for the better or for the worse.⁴³ Given this assumption, if God is perfect, God cannot change. If He changed, He would either become better (which is impossible, since He is already maximally perfect) or become worse (which is impossible, since a perfect being cannot become less than perfect). So, the argument concludes, God must be immutable.⁴⁴

The second reason is the Aristotelian assumption about modality. Classical thinkers took immutability and necessity to be equivalent or at least mutually entailing. A being that undergoes change cannot be a necessary being. Since God is necessary, God must be immutable.⁴⁵

The third reason is scriptural, at least on the surface. Classical theologians appealed to passages like Malachi 3:6 ("For I the LORD do not change"), James 1:17 ("with whom there is no variation or shadow due to change"), and Numbers 23:19 ("God is not man, that he should lie, or a son of man, that he should change his mind") as proof that Scripture teaches immutability.⁴⁶

The fourth reason is the desire to protect God's perfection and reliability. If God could change, the worry runs, He might become untrustworthy. He might fail to keep His promises. He might grow evil, or lose His power, or cease to love us. A good Christian must therefore insist that God cannot change in any way, for only a God who cannot change can be fully trusted.⁴⁷

These are serious reasons, and I want to take them seriously. But I believe each one can be answered, and I want to answer them now.

5. The Case Against Strong Immutability

5.1 Strong Immutability Contradicts the Biblical Portrait of God

The first and most obvious problem is that strong immutability — the claim that God cannot change in any respect — contradicts the overwhelming testimony of Scripture. The Bible does not describe a frozen, motionless God. It describes a God who acts, speaks, judges, creates, redeems, and responds. It describes a God who grieves (Gen. 6:6), who relents (Exod. 32:14, Jonah 3:10), who hears and answers prayer (Psa. 65:2), who rejoices over His people (Zeph. 3:17), who is angry at sin (Num. 11:10) and moved by compassion (Hos. 11:8). Every page of Scripture describes a God in dynamic relationship with His creation.⁴⁸

What about Malachi 3:6 and James 1:17? Let us look at them carefully. Malachi 3:6 reads: "For I the LORD do not change; therefore you, O children of Jacob, are not consumed." Notice the context. God is not making an abstract metaphysical statement about His lack of any potentiality or extrinsic relation. He is making a covenantal statement. The reason the children of Jacob are not consumed by their own sin is that God is faithful to His promises. His covenant love does not waver. That is what "I do not change" means here. It is a claim about God's moral character and covenantal faithfulness, not about His metaphysical inability to undergo any change whatsoever.⁴⁹

James 1:17 makes a similar point: "Every good gift and every perfect gift is from above, coming down from the Father of lights, with whom there is no variation or shadow due to change." Again, the context is about God's reliability as a giver of good gifts. He does not fluctuate like shadows do. His goodness is steady. This is a claim about God's moral consistency, not about His inability to undergo relational change.⁵⁰

Numbers 23:19 is even clearer: "God is not man, that he should lie, or a son of man, that he should change his mind." Here "change his mind" is paired with "lie" — the point is that God is not fickle, not unfaithful, not unreliable like fallen humans. God keeps His word. This says nothing about whether God can genuinely respond to a changing world. (For a fuller exegetical treatment of these passages, see Chapter 19.)

Craig puts the biblical point bluntly: Scripture "at most speaks of God's immutability in terms of His faithfulness and unchanging character."⁵¹ The Bible teaches that God's character does not change, that His promises do not fail, that His love is steadfast. It does not teach that God is frozen in an eternal instant, unable to act, respond, or relate. The classical doctrine of strong immutability is simply not what Scripture is talking about.

5.2 Strong Immutability Entails Timelessness — and Fails With It

A second problem with strong immutability is that it directly entails divine timelessness — and we have seen (Chapter 6) that timelessness itself fails. Here is how the entailment works. A temporal being necessarily undergoes at least extrinsic change: it exists at one moment, and then at the next, and then at the next. Even if nothing about it "changes" in any intrinsic sense, the passage of time itself generates successive temporal relations. As Craig notes, a temporal God "at the very least changes in that He is constantly growing older — not physically, of course, but in the purely temporal sense of constantly adding more years to His life."⁵² Moreover, a temporal God would have constantly changing knowledge (knowing first that "it is now t₁" and then that "it is now t₂"), constantly changing action (causing events at t₁ and later causing different events at t₂), and constantly changing memory and anticipation (as future events become past ones). None of this is compatible with strong immutability.⁵³

So: strong immutability entails timelessness. And if (as I have argued throughout this book and especially in Chapters 6 and 27) timelessness is incompatible with creation ex nihilo, with the incarnation, with divine foreknowledge of tensed facts, and with genuine divine action — then strong immutability is also incompatible with all of those things. The doctrine that seems at first to protect divine perfection ends up undermining the central plotlines of the Christian story.⁵⁴

5.3 Strong Immutability Entails Impassibility — and Fails With It

Strong immutability also entails strong impassibility — the view that God cannot be affected in any way by anything outside Himself. This is because genuine emotional response requires change. If God is moved by His people's suffering, or stirred by their praise, or grieved by their sin, then something in God is different as a result of what happens in the world. But strong immutability rules out any such difference. A strongly immutable God cannot be responsive, because responsiveness is a kind of change.⁵⁵

The classical tradition understood this perfectly well. Aquinas, for example, concluded that God is not, strictly speaking, merciful, because mercy requires feeling sorrow — and a strongly immutable God cannot feel sorrow. "The effects of God, according to Aquinas, may be said to be merciful, but God Himself is not literally merciful."⁵⁶ That is a stunning claim. It says that the God of Scripture, who is repeatedly described as "rich in mercy" (Eph. 2:4), is not, strictly speaking, merciful. His acts appear merciful to us, but He Himself does not experience mercy. He does not feel compassion. He does not suffer with His people.

This is the God of classical theism taken to its logical conclusion. And most Christians, when they see where it goes, recoil — and rightly so. The God of the Bible is not a frozen statue. He is a living Father who "feels deeply" for His people (cf. Hos. 11:8). (I develop this argument at length in my companion book on divine emotion, The Heart of God, and in Chapter 28 of the present book.) If we reject impassibility because it contradicts the biblical portrait of a responsive God, then we must also reject the strong immutability that entails it.⁵⁷

5.4 Strong Immutability and the Oppy Causal Principle

A fourth objection, pressed sharply by Mullins, comes from what we might call the causal principle problem. The philosopher Graham Oppy has argued, and Mullins has developed, the point that causing a new effect requires a corresponding change in the cause. If I cause the light to turn on at 9:00 PM, then something about me at 9:00 PM is different from what I was at 8:59 PM — at the earlier time I was not causing the light to turn on, and at the later time I am. This is true not just of physical causation but of any kind of causation.⁵⁸

Apply this to God. If God causes the universe to exist at one moment (creation), then something about God is different from what He was "before" creation. He was, so to speak, "not causing the universe to exist" and then "causing the universe to exist." That is a change. If God causes the Red Sea to part, and earlier was not causing the Red Sea to part, that is a change. If God caused the incarnation at a particular point in salvation history, and before that was not causing the incarnation, that is a change. Every divine action generates a corresponding change in God.⁵⁹

The classical theologian has only one response available: to deny that God really causes anything in the world at specific times. Instead, God must cause everything in "one eternal act" that stands outside of time. This is a clever move, but it has terrible consequences. It means that God cannot respond to prayer (since response requires a change). It means that God cannot intervene in history (since intervention is causation at a time). It means that God's miracles are not really God "acting" at particular moments but rather eternal features of the one divine act as it is realized in time. This picture of God is simply not what the Bible teaches. Scripture shows a God who acts at particular times — who chooses Abraham, who calls Moses, who sends His Son in the fullness of time, who pours out His Spirit at Pentecost. If divine action is real, then strong immutability must go.⁶⁰

5.5 Strong Immutability Conflicts With Genuine Divine Freedom

A fifth problem: strong immutability conflicts with divine freedom. If God cannot change in any respect, then God cannot have freely chosen to create this world rather than some other world, or no world at all. For if He could have chosen otherwise, then He had the potential to be a God-who-creates-world-B rather than a God-who-creates-world-A. And potentiality, on the classical view, implies mutability.⁶¹

Craig puts this neatly: "It is also not clear that divine immutability (as opposed to mere changelessness) is compatible with divine freedom — suppose God wanted to change?"⁶² That is a very good question. If God is genuinely free — if He could have done otherwise — then He has unrealized potential. But strong immutability denies that God has any unrealized potential. So either God is not free in any robust sense, or God is not strongly immutable. Most Christians would sooner give up strong immutability than give up divine freedom. Scripture everywhere assumes that God freely created, freely chose to redeem, freely sent His Son, freely poured out His Spirit. If those acts were really free, then strong immutability must be softened.

5.6 Strong Immutability Is Not Actually a Perfection

Finally, we might ask the most basic question of all: why think that strong immutability is a perfection in the first place? Classical theologians assumed it was. But why?

Craig raises the issue beautifully: "Divine immutability is sometimes said to be a necessary correlate of divine perfection. But this seems clearly incorrect. A perfect being need not change 'vertically,' so to speak, on the scale of perfection and, hence, for the worse, but could change 'horizontally,' remaining equally perfect in both states. For example, for God to change from knowing 'It is now t₁' to knowing 'It is now t₂' is not a change for the worse in God; on the contrary, it is a sign of His perfection that He always knows what time it is."⁶³

In other words, there is no reason to think that every change is a change for the better or worse. A perfect being can remain perfect while undergoing relational and cognitive changes that track reality accurately. Indeed, such responsiveness is itself a kind of perfection. A God who cannot hear a prayer as it is prayed, cannot notice a sparrow as it falls, cannot grieve with the grieving or rejoice with the rejoicing — such a God is lacking something real. He is lacking responsiveness to His creation. That is not a perfection but a deficiency.⁶⁴

Mullins makes a similar argument from the opposite direction. He points out that it is not obvious at all that existing without succession or change is "a property that it is intrinsically better to have than not have."⁶⁵ The classical theist has to do serious work to establish immutability as a great-making property, and that work has not been done convincingly. At best, it rests on the contested Platonic assumption that all change is for the better or worse — an assumption that most contemporary metaphysicians no longer accept.⁶⁶

6. What Should Be Preserved: Qualified Immutability and Weak Simplicity

At this point, someone might worry that I have been too harsh. After all, the doctrines of divine simplicity and immutability did not come from nowhere. They were developed by serious theologians wrestling with serious concerns. What about those concerns? Are we just going to throw them overboard and say that God has parts and changes however He likes?

Not at all. My goal in this chapter is not to jettison simplicity and immutability wholesale but to reform them. What classical theologians were trying to protect — God's aseity, God's independence from creation, God's reliability, God's perfection — are all things the Bible clearly teaches. But the classical formulation of these doctrines went too far. What we need is a version of simplicity and a version of immutability that preserves what Scripture teaches while shedding the problematic Greek metaphysical baggage that has clung to them for so long. I will call these weak simplicity and qualified immutability.

6.1 Weak Simplicity: God Is Not Composed of Separable Parts

Weak simplicity is the claim that God is not composed of separable parts. It affirms that God is not made up of pieces that were put together, that could be taken apart, or that could exist independently of one another. God's attributes are not like ingredients in a recipe, where each could be removed and the rest remain. Rather, God's attributes are all essential to Him — you cannot have God without love, or without justice, or without knowledge — and they are all deeply unified in the one divine being.⁶⁷

At the same time, weak simplicity allows for real distinctions in God. It says that God's love is not identical to God's justice in the strict metaphysical sense, even though both flow from the one divine nature. It says that the three Persons of the Trinity are really distinct from one another, even though they share one divine essence. It says that God's willing to create is distinguishable from His willing to redeem, even though both are expressions of one and the same holy God.

Mullins calls this position "divine unity" rather than "divine simplicity," and I think that is a helpful way to put it. He writes that on this view, God's essential attributes are "unified in that they are necessarily co-extensive and compossible. As co-extensive, one will not find God's power floating free from God's wisdom, nor will one find any of God's essential attributes floating free from God. As compossible, all of God's attributes are internally consistent with one another."⁶⁸

This version of simplicity preserves everything the Bible teaches. God is one. God is not made of parts. God's essential attributes cannot be separated from His being. God does not depend on anything outside Himself for anything He essentially is. But weak simplicity avoids all the disasters of the strict classical version. It allows for the Trinity. It allows for real relations between God and the world. It allows for meaningful theological distinctions. It allows for genuine divine freedom and responsiveness. It is, I believe, what the Bible actually teaches when it says that God is one.

6.2 Qualified Immutability: God's Character Never Changes, But God Truly Responds

Similarly, we do not need to abandon every form of immutability. What we need is qualified immutability — the view that God's essential nature, His moral character, and His foundational purposes do not and cannot change, even though His relational states, emotional responses, and actions in the world genuinely vary in time.⁶⁹

Qualified immutability affirms everything Scripture actually says about God's unchangingness. God's love never fails (Lam. 3:22). God's counsel stands firm forever (Psa. 33:11). God's covenant promises endure from generation to generation. God's holy character does not waver. The God who delivered Israel from Egypt is the same God who sent His Son in the fullness of time, and He is the same God who will come again in glory at the end of the age. In all that matters for our salvation, our trust, and our hope, God is absolutely reliable. He is the "Father of lights, with whom there is no variation or shadow due to change" (James 1:17).

But qualified immutability denies the further classical claim that God cannot undergo any extrinsic or relational change whatsoever. God genuinely becomes the creator of the universe at the moment He creates. He genuinely becomes incarnate at the moment the Word takes on flesh. He genuinely responds to our prayers, genuinely grieves over sin, genuinely rejoices in repentance. These are real changes in God — not changes in His essential nature, but changes in His relational and active life. They do not make God less perfect. If anything, they make God more fully the living God of Scripture rather than the frozen abstraction of Greek philosophy.⁷⁰

Mullins captures the point well: "Neoclassical theism thinks that God's power and freedom entail the ability to change in certain respects, such as becoming the creator and saviour of the universe."⁷¹ Mullins worries about the term "weak immutability" because it might suggest that God is only partly immutable, when really the neoclassical view is simply that God is mutable in some respects (relational and active) and immutable in others (essential nature, character, purposes). I think either way of putting it works, so long as the substance is clear: God does not change in the ways that would make Him unreliable, but He does change in the ways that make Him responsive.⁷²

6.3 A Biblical Anchor: The Unchanging Character of a Changing Relator

It is important to see that the Bible itself models this distinction. God's character is unchanging: He is always holy, always loving, always just, always faithful. But God's relations with creatures change constantly. He was not always a creator (there was a "time" — in divine time, generated by the Trinity's perichoretic life — when there was no creation for Him to be creator of; see Chapter 26). He was not always incarnate (there was a time when the Son had not yet taken on flesh). He was not always responding to Peter's particular prayer (because Peter had not yet prayed it). But in all these changing relations, God's underlying character has never wavered. The same loving Father who walked with Adam in the garden also wept over Jerusalem, also suffered on Calvary, also called Saul on the Damascus road, also hears my prayer this morning.

This is what qualified immutability protects. It lets God be genuinely unchanging in everything that matters for our salvation, while also being genuinely alive, genuinely active, and genuinely responsive. It is the best of both worlds — and, I believe, what Scripture has taught all along.⁷³

7. The Interlocking Package: Simplicity, Immutability, Impassibility, Timelessness

I want to close this chapter by stepping back to see the big picture. One of the most important things Mullins has emphasized in his work is that the classical divine attributes — simplicity, immutability, impassibility, and timelessness — are not four independent doctrines that happen to sit next to each other on a list. They are, as he puts it, "a very tight package."⁷⁴ They stand together or they fall together.⁷⁵

Let me show how the package works. Start with simplicity. If God is strictly simple, then He has no real distinctions in His being — no succession, no real attributes, no potentiality. From this it follows that God cannot change (immutability), that God cannot be affected emotionally (impassibility), and that God cannot have a before-and-after in His life (timelessness). Conversely, start with timelessness. If God is timeless, He has no succession; therefore He cannot change (immutability); therefore He cannot be emotionally affected (impassibility); and since there is no succession in His being, there cannot even be conceptual distinction in His life (simplicity). The four doctrines are mutually entailing in classical theology. Pull one thread, and the whole sweater begins to unravel.⁷⁶

This is why Chapter 30 has to exist in this book. Throughout the earlier chapters I have been arguing against divine timelessness on a variety of grounds: biblical (Chapter 6), christological (Chapter 27), emotional (Chapter 28), and from divine action (Chapter 29). But as long as strict simplicity and strong immutability remain in place, the sophisticated defender of timelessness can always reply: "Your biblical and theological arguments are interesting, but they cannot outweigh the philosophical necessity of timelessness, which follows from simplicity and immutability. God must be timeless because He is simple and immutable." To fully defeat divine timelessness, we need to pull out its philosophical foundations. That is what I have tried to do in this chapter.⁷⁷

And notice the beautiful reverse logic. If we affirm qualified immutability and weak simplicity — the modified doctrines I have proposed — then the package comes unbound in a positive way. Qualified immutability is compatible with divine temporality: God can change relationally without changing in His essential nature. Weak simplicity is compatible with divine temporality: God can have genuine distinctions in His life (including before-and-after) without being composed of separable parts. The doctrines that once entailed timelessness now fit comfortably with temporality. The package has not been destroyed; it has been rebuilt on better foundations — foundations that match the biblical portrait of God rather than the metaphysical demands of Plotinus.

8. Answering the Most Serious Objections

Before I close, I want to address the most serious objections a thoughtful classical theist might raise against the position I have defended.

8.1 "Doesn't Rejecting Simplicity Turn God into a Creature?"

First objection: if God has real distinctions in His being, doesn't that make Him a creature, or at least creature-like? Classical theologians have often argued that creatures have properties, participate in universals, and are composed of essence plus existence — whereas God, being the Creator, must be fundamentally different. To give up strict simplicity seems to drag God down to the creaturely level.⁷⁸

My response: No. Rejecting strict simplicity does not turn God into a creature. God is still utterly different from creatures in many ways: He is uncreated, necessary, eternal, omnipotent, omniscient, omnipresent, morally perfect, and the source of all else that exists. He does not depend on anything outside Himself for His being or His essential nature. He is not composed of separable parts. All that remains. What we are rejecting is the specific Neoplatonic claim that God must be metaphysically undifferentiated — an absolute unity without any internal complexity. That claim is not what makes God the Creator. What makes God the Creator is His uniqueness, necessity, aseity, and infinite perfection. Weak simplicity preserves all of these. It just refuses to reduce them to the extreme metaphysical formula that makes Christian theology incoherent.⁷⁹

8.2 "Doesn't Qualified Immutability Make God Unreliable?"

Second objection: if God can change, even relationally, how can we trust Him? What if He changes His mind tomorrow and sends us to hell? What if His love fades over time?

My response: qualified immutability explicitly affirms that God's essential nature, His moral character, and His covenant promises never change. What can change is God's particular relational states — His response to our prayers, His joy at our repentance, His grief over our sin. These changes flow from God's unchanging character, not against it. In fact, it is precisely because God's love is unchanging that He truly grieves when His beloved creatures suffer and truly rejoices when they are restored. A frozen, unresponsive God would be less trustworthy, not more. The Father of the prodigal son is utterly reliable in His love — and that is exactly why He runs down the road to meet his returning son (Luke 15:20). A truly loving God must be genuinely responsive, and a genuinely responsive God must be able to undergo relational change. Qualified immutability is not a weakening of God's reliability; it is its proper foundation.⁸⁰

8.3 "Doesn't This Undermine God's Aseity?"

Third objection: if God is really related to the world and really responds to creaturely actions, doesn't that make God dependent on creation in some way, undermining His aseity (His complete self-existence)?

My response: Not if we are careful. Aseity, properly understood, is the claim that God's existence and His essential nature do not depend on anything outside Himself. On that definition, there is no conflict between aseity and God's being really related to the world. God exists necessarily and in His essential nature independently of creation. But He has freely chosen to create a world and to enter into real relations with it. Those relations are contingent — God did not have to create — but once God has freely created, the relations He sustains with His creatures are real. God's reality as Creator is not something He needs in order to be God; it is something He freely takes on. The dependency objection confuses necessary features of God's essential nature with contingent features that God freely chooses to have.⁸¹

Mullins is helpful here: "Aseity is a claim about the existence of God. Self-sufficiency is a claim about the nature of God. Given the classical theist's commitment to divine simplicity, aseity and self-sufficiency are identical to one another. However, other theists who reject divine simplicity do not need to make this identity claim."⁸² Once we distinguish aseity from simplicity — as we should — the objection falls apart. God can be a se (self-existent) and self-sufficient without being strictly simple, and therefore without being incapable of real relation to the world.

8.4 "Haven't the Church Fathers and Reformers All Affirmed These Doctrines?"

Fourth objection: rejecting classical simplicity and strong immutability sets us against the vast majority of the Christian theological tradition. The church fathers taught them. The medieval schoolmen taught them. The Reformers largely taught them. Are we really going to say that all of these great theologians were wrong?

My response: First, we should acknowledge that there is, in fact, a long minority tradition in Christian thought that has questioned or rejected strict simplicity and strong immutability. Mullins notes that within Islamic philosophy, for instance, "there are plenty of medieval Islamic philosophers and theologians who reject divine simplicity... Al-Ghazali is a well-known example of this, but the Islamic rejection of divine simplicity is actually much older."⁸³ Within the Christian tradition, Isaac Newton, Samuel Clarke, William of Ockham, and Peter of Ireland all affirmed forms of divine temporality; "some scholars say that divine temporality was the majority view at Oxford in the early 14th Century."⁸⁴ So the claim that "everyone" affirmed classical simplicity and strong immutability until recently is historically oversimplified.

Second, and more importantly, the authority of the theological tradition is not absolute. The tradition is useful, valuable, and to be taken seriously. But it is not infallible. The Protestant Reformers themselves broke with many aspects of the medieval tradition, and we Protestants have always recognized that sola Scriptura means that even widespread theological consensus can be revised when Scripture itself demands it. Where the tradition stands in tension with clear biblical teaching — as I have argued strict simplicity and strong immutability do — we must side with Scripture.

Third, we are not saying the fathers and schoolmen were foolish. They were brilliant, and they were working with the best philosophical resources available to them. But those resources included substantial amounts of Platonism and Aristotelianism that have since been heavily critiqued, both philosophically and biblically. In many ways, the development of analytic philosophy in the 20th and 21st centuries has given us tools — better tools — for examining these ancient claims. We owe the fathers enormous gratitude for preserving and extending the faith, but we do not owe them uncritical agreement on every metaphysical point.

9. The Pastoral Significance of Rejecting Strict Simplicity and Strong Immutability

I want to end this chapter by pointing toward something I will develop more fully in Chapter 35 but that I cannot leave out here entirely. The debate over divine simplicity and strong immutability is not merely a dry philosophical dispute. It matters pastorally. It shapes how we understand God in our prayers, in our suffering, in our worship, and in our daily walk with Him.

Think about what it means to pray to a strongly immutable, strictly simple God. You kneel by your bed. Your child is dying. You beg God for healing. If strict classical theism is right, then your prayer does not really reach God in any way that changes Him. He does not really hear you at this moment, because "moments" do not apply to Him. He does not really feel your pain, because pain is a passion and a simple God cannot have passions. He does not really change anything in response to your prayer, because response implies change. Whatever happens — healing or death — is what God eternally, changelessly decreed. Your prayer is, in the strictest sense, causally and emotionally irrelevant to God Himself. It may be a good spiritual exercise for you, but it does not do anything to God.⁸⁵

Now think about praying to the God we have actually found in Scripture — the God of qualified immutability and weak simplicity. You kneel by your bed. Your child is dying. You beg God for healing. This God really hears you. In this very moment, as you pour out your heart, He is receiving your cry. He is moved by your suffering, though not controlled by it. His eternal, unchanging character of love is expressing itself in a real, specific, temporal response to your specific prayer. He knows what you are feeling because He is right there with you, and He is responding to you — either by granting what you ask, or by sustaining you in the loss, or (often) by meeting you in ways you did not expect. This God is the Father Jesus talked about — the Father who clothes the lilies and counts the hairs on your head (Matt. 6:28-30, 10:30). Not a frozen absolute. Not a Platonic Form. A living, loving, responsive Person.⁸⁶

Which God is the God of the Bible? Which God is the God Jesus revealed? Which God do we meet when we come to Him in prayer? I am fully convinced that the answer to all three questions is the same. The God of Scripture is the God who genuinely hears, genuinely responds, genuinely loves in time, genuinely acts in history. And to meet that God, we must let go of the frozen, undifferentiated absolute of classical metaphysics. We must let strict simplicity and strong immutability go.

10. Conclusion: A Better Foundation

In this chapter I have argued that the classical doctrines of strict divine simplicity and strong immutability must go. They fail philosophically: strict simplicity collapses God's attributes into empty identity claims, makes theology impossible, endangers the doctrine of the Trinity, and destroys the reality of God's relation to the world. Strong immutability contradicts the biblical portrait of God, entails timelessness and impassibility (both of which we have seen to be unsustainable), conflicts with divine freedom, and fails to meet the standards of a great-making property. Both doctrines are largely imported from Greek philosophy rather than derived from the pages of Scripture. Both must be rejected in their classical forms.

But we do not leave the doctrines of God bare. In their place we affirm weak simplicity (God is unified, not composed of separable parts, though His attributes are genuinely distinguishable) and qualified immutability (God's essential nature and moral character do not change, though His relational states, emotional responses, and active interactions with creation genuinely vary in time). These modified doctrines preserve everything biblical and philosophically sound in the classical tradition while shedding the metaphysical excesses that have led so much of Christian theology into trouble.

And here is the crucial payoff for the argument of this book: once strict simplicity and strong immutability are replaced by their qualified versions, the last real philosophical arguments for divine timelessness collapse. The "tight package" of classical attributes comes apart, and temporal theism is left standing as the more biblically faithful, philosophically coherent, and pastorally satisfying alternative. What we have done in this chapter is not so much to demolish a tradition as to re-found it — on Scripture, on careful philosophy, and on the living God who has revealed Himself in Jesus Christ.

In the next chapter, we will turn to the question of relativity, physics, and the theology of time. There, we will see that even modern physics, despite initial appearances, does not force us back into timelessness. But first, we have done the hard work here: the philosophical foundations of classical timelessness — strict simplicity and strong immutability — have been examined and found wanting. They must go. And the God who remains, the God of qualified immutability and weak simplicity, is the God of the Bible: the Father, Son, and Holy Spirit who is one in essence, three in Person, genuinely temporal, genuinely loving, and genuinely present to every moment of His creatures' lives.