There are several dividing lines between those who identify as Reformed Christians today. There always are a few. What has become the most decisive point of contention regards the doctrine of God. That may seem surprising. We are speaking about a group of people who are, by all other accounts, conservative, confessional, Calvinistic, Bible-believing Christians. So how could our doctrine of God be up for debate? I will not tax the reader with a review of how all this came to the surface over the past ten years. But I do think it is important to define terms for people who would otherwise get lost in a discussion that is already downstream. One such term is “classical theism.” 

Distinctions for Distractions before Definitions

Classical theism is obviously some designation about belief in God (theism). It is called “classical” because it represents that theology characteristic of orthodoxy as a whole. The adjective classical ordinarily modifies something (e.g., architecture, music, philosophy) that exists in its greatest form. Naturally this raises the eyebrows of the modern debunker of all things excellent—“Oh, and who gets to decide that?” comes the predictable rabbit trail.

Two other misgivings immediately present themselves about the words. First, when it comes to the history of the West, thinking which is “classical” really owes itself to ancient Greece and Rome, and that spells paganism. Second, why call a Christian theology a mere “theism,” let alone tie a supposedly most excellent theology down to this generic label? A polytheist is a theist of sorts. So is a Muslim, with his belief in Allah. So is a Deist, with his “Nature’s God.”

While I do think that these are usually red herrings, since our aim is to be clear and remove any unnecessary obstacles, I am occasionally happy to use the labels “classical theology” or “classical Christian theology” if it will help anyone off the path of distraction. However, I would caution the overly-cautious that the debate here is not over a mere verbal disagreement, but a real disagreement over the substance of what we attribute to God.

God in Himself

What characterizes the very substance of classical theism is understanding that God is God in Himself, first and foremost, and that He has revealed Himself (a) in His works (effects), in ways fitting for the capacities of creaturely understanding, yet (b) not so as to confuse these effects with His essence. Put in philosophical terms: the narrative and relational depictions of God in Scripture, while perfectly true, are not meant to be an alternative to metaphysics—not a God in space and time as opposed to the eternal God, not a God in the grace of Christ as opposed to the First Cause of nature, not a God who sympathizes with our weaknesses as opposed to divine impassibility, and so forth.

It was pious-sounding of brilliant Pascal to speak of the God of Abraham, Isaac, and Jacob as opposed to the “god of the philosophers.” But what do we mean by this? Modern theology means to drive a wedge in between theology and metaphysics—that is, between what is “personal” and what is essential, between what is “biblical” and what is, well, what “is.” They may not like that characterization, but that is the gist of it. Hence what has been called “theistic personalism” and what has been called “biblicism” fit together like a hand in a glove.

It is a paradox of Christian theology that we know the triune God only because of His self-revelation. The aseity and the infinity of God on one end, and the finitude and sinfulness of man on the other, imply a multi-layered hiddenness of God. The Barthians were not wrong to exalt God’s freedom to reveal. Deuteronomy 29:29 says as much. Where they were wrong is to define God’s essence down to the effects of that freedom, making God identical to the revelation that was so fit. The idea was that God is what He freely chose to be for us in Christ—being-in-act. But even John’s Gospel prologue reminds us that Christ is eternally the Word (1:1), and, secondarily, “became” flesh (1:14).

That which simply is in God has a priority over that in which He condescends for us and for our salvation. And that “priority” is what classical Western philosophy called metaphysics: the study of being.

You may have heard, here or there, that such thinking was a Greek “intrusion” into the early faith that was otherwise devoted to the pure biblical text. Do you know where you heard that from? On a theoretical level it came gradually throughout the Enlightenment, but it was practically canonized by the liberal Adolf von Harnack at the turn of the twentieth century. Though the reasons may not be appreciated, the fact that the early church fathers, medieval scholastics, and, yes, the earliest Reformed theologians, all embraced this metaphysical picture of God, is indeed a fact to be reckoned with by the honest student of church history.

These classical theologians were well aware that, due to our finitude and sin, God must introduce Himself to mankind in a narrative form, from left to right, so to speak, and in a way that confounds fallen reason’s expectations; but they also knew that (when we are talking about rightly ordering doctrine: i.e., systematic theology), who God is in Himself must come first and remain fixed as we continue to return, again and again, to the specially revealed narrative. 

Why Does This Matter?

Christian theology always has a responsibility to show why its business is practical to real people. This subject especially, being of the highest things, carries that burden. So let us get right to it. When you read an author or hear a sermon depicting the Son as eternally subordinate to the Father, and in such a way as to suggest three separable wills in the Godhead, what you have received is a consequence of the loss of classical theism. When the sovereignty of God is defended only by the suggestion that God could have willed to be more or less immutable, more or less omniscient, or that He could have commanded, “Thou shalt have other gods before me” after all, then what you are dealing with is the attempt to have Reformed orthodoxy without classical theism—a mistake that the first few centuries of Reformed theologians did not in fact make. 

For Further Reading

G. L. Prestige, God in Patristic Thought (London: SPCK, 1936)

Étienne Gilson, God and Philosophy (New Haven: Yale University Press, 1941)

E. L. Mascall, He Who Is: A Study in Traditional Theism (New York: Longmans, Green and Co., 1943)

Matthew Levering, Scripture and Metaphysics: Aquinas and the Renewal of Trinitarian Theology (Malden, MA: Blackwell Publishing, 2004)

James Dolezal, All That Is in God: Evangelical Theology and the Challenge of Classical Christian Theism (Grand Rapids: Reformation Heritage Books, 2017)

Joseph Minich & Onsi A. Kamel, ed., The Lord is One: Reclaiming Divine Simplicity (Davenant Press, 2019)

Steven Duby, God in Himself: Scripture, Metaphysics, and the Task of Christian Theology (Downers Grove, IL: InterVarsity Press, 2019)

Steven Duby, Jesus and the God of Classical Theism: Biblical Christology in Light of the Doctrine of God (Grand Rapids: Baker Academic, 2023)

Craig A. Carter, Contemplating God with the Great Tradition: Recovering Trinitarian Classical Theism (Grand Rapids: Baker Academic, 2021).

Matthew Barrett, The Reformation as Renewal: Retrieving the One, Holy, Catholic, and Apostolic Church (Grand Rapids: Zondervan, 2023)