Understanding Nicene Trinitarianism


Nathan A. Jacobs

Article ID:



May 24, 2024


Dec 21, 2020

This article first appeared in the Christian Research Journal, volume 41, number 4 (2018). For more information about the Christian Research Journal, click here.



The doctrine of the Trinity was articulated by the church fathers in the councils of Nicea (AD 325) and Constantinople (AD 381), which penned the Nicene Creed. We will see that Nicene Trinitarianism teaches the Trinity is three hypostases and one ousia, terms often translated as three persons and one essence, substance, or being. These terms, in their ancient Greek context, indicate that the Trinity is three subjects who share a single nature. However, this formulation naturally raises the question whether Nicene Trinitarianism is monotheistic. In affirmation of Nicea’s monotheism, we will see that all three uses of the word “God” in Christian theology are singular, despite the Trinitarian plurality of subjects. Hence, Nicene Trinitarianism is rightly labeled monotheistic, even though it is a unique type of monotheism. We will then look at three important differences between God and creatures that must be kept in mind for a proper understanding of Nicene Trinitarianism. These are (1) the divine subjects are not spatially or materially separated the way created individuals are; (2) the divine subjects, unlike created individuals, are distinguished by their relations to one another and not by material accidents of size, color, or location; and (3) because the divine subjects are differentiated by their relations, they, unlike created individuals, have no autonomous existence apart from one another.


Prior to AD 1054, the Christian church was one. Though it was divided regionally and linguistically, it had one Lord, one faith, and one baptism. During this first thousand years, the doctrines of Trinity and Christology were the center of Christian theology. Though discussions about other topics abound, such discussions, rightly understood, were extensions of the Trinitarian and Christological teachings of Christianity. Regrettably, these doctrines are some of the least understood today, and many contemporary writers both knowingly and unknowingly propagate ancient heresies.1 I want to help remedy this state of affairs by giving an overview of Trinitarianism as articulated at the councils of Nicea and Constantinople, which penned the Nicene Creed.

Whenever teaching on Trinitarianism, I begin by asking what explanations of the Trinity folks have heard. The analogies fall into three groups. The first set of analogies uses parts–whole explanations. For example, the Trinity is like an egg, which has a shell, egg white, and egg yolk. The second set of analogies applies several names to one subject. For example, one man can be a husband, a father, and a son. The third set of analogies identifies a single substance that can take on different states. For example, H20 is one compound that can be a solid, liquid, or gas.

The difficulty with these sets of analogies is that each represents an ancient heresy. The H20 analogy suggests the divine nature is like a substratum that produces several persons. This way of thinking is identified by Basil of Caesarea (third-century defendant of Nicene Trinitarianism) as impious and blasphemous — not a raving endorsement.2 The set of analogies that uses three distinct names for one subject comes closest to the more well-known heresy Sabellianism. Sabellius taught that God is like an actor wearing several masks — Father, Son, and Spirit. But behind these faces is just one person.3 As for parts–whole analogies, this comes closest to the heresy known as Tritheitism. Tritheitism, also called the “ravings” of John Philoponus, argued that the divine nature is divided into three parts, analogous to a lump of clay cut into three.4

One response to the realization that common analogies for the Trinity are heretical is that all analogies are flawed, so the flaws are no big deal. The problem with this reply is it presumes all analogies are false simply because they are analogies. However, Christian theology has always held that all of our talk of God is analogical. When we say God is wise, we do not mean the same thing we mean when we say Solomon is wise. When we say God is powerful, we do not mean the same thing we mean when we say the president is powerful. Nonetheless, what we say analogically is subject to truth or falsehood.5 It is analogical to say that the Lord is my shepherd (Ps. 23:1). It is also analogical to say (God forbid) that God is a cheat. The former statement is true, while the latter is false and blasphemous. The Nicene Creed, too, says something analogical about the Trinity, and what it says is in opposition to analogical falsehoods about the Trinity. Not all analogies are made equal, and the above all-too-common analogies say something contrary to the faith once delivered to the saints (Jude 1:3).


So what is Nicene Trinitarianism? The basic profession in Greek is one ousia and three hypostases. These words are often translated into English from Latin equivalents as three “persons” and one “substance,” “being,” or “essence.” Such translations can be misleading, however, given the ambiguity of these English terms. But the original Greek terms were anything but ambiguous among the church fathers.

Let us begin with the Greek term ousia. Ousia refers to the nature or essence of a thing. For example, let’s say I have before me three individuals named Jan, Erik, and Steve. The ousia of these three is human. This is the nature shared by these individuals. Likewise, if I had before me Lassie, Rover, and Rufus, the ousia of these three would be dog.

Regarding the term hypostasis, this word indicates an individual or particular subject.6 Using the same examples, I can say that Jan, Erik, and Steve are three individuals or subjects. Likewise, Lassie, Rover, and Rufus are three individuals or subjects.

In the most basic sense, then, Nicene Trinitarianism affirms that the Father, Son, and Holy Spirit are three distinct individuals or subjects who share a common nature, namely, the nature God. This is what it means to confess that the Holy Trinity is three hypostases of one ousia. Such a coupling of one and three is neither contradictory nor unusual. In fact, it is common to find in our world several hypostases that share one ousia. In each of the above examples, we find the very thing affirmed of the Holy Trinity. And lest anyone think this is my own novel solution to the three–one problem, allow me to quote Basil of Caesarea’s letter on Nicene terminology: “The distinction between ousia and hypostasis is the same as that between the general and the particular; as, for instance, between the animal [human] and the particular man.”7

This is our starting point. The Nicene profession is that there is only one divine nature, and only three individuals have it: the Father, the Son, and the Holy Spirit. Of course, qualifications must be added about the differences between created subjects and divine subjects. But this is always the case. As noted above, when we say God is wise and Solomon is wise, we do not mean the same thing. The analogy is true, but it requires caveats. And so it is in our profession of three divine subjects of one nature. The statement is true, and it is what the Nicene faith professes. But it too requires caveats.

Three Uses of the Word God

Before stating these caveats, however, I suspect some readers may be asking themselves, Does Christianity profess three Gods? Some may be uneasy with this profession because, on the face of it, it sounds polytheistic. As Tertullian once noted, some in his day who had turned from polytheism to Christianity were surprised to learn that God has a Son.8 Are Christians really monotheists? One way of addressing this question is to look at the three uses of the word God in Christian theology.

The first and most common referent for the word God is the Father. This is common throughout the New Testament, and it echoes in the Nicene Creed: “I believe in one God, the Father [etc.].” This use is certainly singular. For there is only one Father.

The second use is in reference to the divine nature shared by Father, Son, and Holy Spirit. This use appears in the prologue to the Gospel of John: “and the Word was God” (John 1:1). John is not saying the Word was the Father, nor is he saying the Word was the Trinity. He is using God (theos) in the predicate nominative, identifying the type of thing the Word is — just as I would say, Bob is human. In a letter to Ablabius, Gregory of Nyssa explains the singularity of this use of God. Ablabius asked Gregory whether Christians profess three Gods, since Peter, James, and John are three hypostases of one ousia, and we call them three humans. Gregory replied by identifying this way of speaking (i.e., “three humans”) as a common abuse of language. For human is a species term, and Peter, James, and John are not three species. If we were precise, we would say they are three human (singular) subjects (plural). For their nature is one; the number of individuals is many. And so it is with the Father, Son, and Holy Spirit. We do not profess three Gods, since God indicates the divinity shared by the three. Christianity professes only one divinity, even though three have it.9 The point was crucial to the church fathers. For it was central to differentiating Trinitarianism from polytheism: the polytheists believed in many species of god (i.e., many divinities), while Christianity professed only one divine nature.‑

A third use of the word God is in reference to the entire Trinity. I should warn that this third use is alien to Greek literature of the first millennium.11 But because this use is common in Western literature, I will include it. This use is perhaps the most suspect in its singularity, but it should pass the monotheistic test. When asking, How many Holy Trinities are there?, the answer is One. That the Trinity is three subjects doesn’t falsify the point. For if I asked, How many classes on the Trinity are offered at Calvin Seminary?, the answer would be One. That numerous students are in the class is irrelevant. The question concerns the class, not the attendees.

Therefore, whether we use the word God in reference to the Father, the divine nature, or the Trinity, our use is singular. Christians are thus rightly called monotheists. For we believe in one God — whether we mean one Father, one divinity, or one Trinity.

Having said this, we should not pretend that Christian monotheism is no different than the monotheisms of Islam or Judaism. Christian monotheism agrees with these faiths that there is only one divine nature, and that polytheism errs in professing many divinities. But anti-Trinitarian monotheisms deny that several subjects have the divine nature. They deny that God is a Father who has begat a Son and spirated a Spirit. Christianity cannot agree. As Gregory of Nyssa warns, we must “prevent our argument in our contention with Greeks [i.e., the polytheists] from sinking to the level of Judaism.”12 This statement may be shocking, since many Christians put great effort into smoothing away differences between Judaism and Christianity. It should be obvious, however, that those who affirm the Trinity disagree with those who deny the Trinity. If your understanding of God is no different than that of someone who rejects the Trinity, you’re not a Trinitarian. Christians are monotheists. But more fundamentally, Christians are Trinitarians. This monotheism is unique.

Speaking Analogically

I said above that when we speak of God, we speak in analogies. Saying that God repented (Gen. 6:6; Exod. 32:14) can bring to mind imperfections unworthy of God. There is something true (analogically) about saying that God repented, but we must remember God repents without any of the imperfections of creaturely repentance. And so it is with the profession of three subjects of one nature. The profession is true, but it must not lead to ascribing creaturely imperfections to God. So what qualifications must be kept in mind when speaking of three divine subjects?13

(1) No Material Division. The first misstep to avoid concerns material division. When we think of three created individuals, we think of bodies that are separated by spatial intervals. For this reason, we may be tempted to think of the Father, Son, and Holy Spirit as three separate bodies. But this would be a mistake. God is immaterial. In fact, the church fathers identify this as a fundamental difference between God and creatures: all creatures are finite and material, while God alone is immaterial and infinite.14 We must not, therefore, take the distinction of Father, Son, and Holy Spirit to indicate spatial separation. The Father, Son, and Holy Spirit are three distinct subjects, not three separate bodies; distinction and separation are not the same.

This error cuts two ways, however. Yes, it would be a mistake to think of three separate bodies, but the flipside of this error is to think of the Trinity as materially conjoined. Many are so concerned with professing one God that they fall into the error of collapsing the three into one lump — as happens in parts–whole analogies, for example. Yet to think of the Trinity in this way is to fall into the same error. For whether we think of the subjects as materially separate or materially conjoined, we are thinking of material. The key to Nicene thinking is to abandon materiality altogether. The Father, Son, and Holy Spirit are not material.

(2) Distinguished by Relationship to One Another. A second difference between God and creatures concerns how the Father, Son, and Holy Spirit are distinguished. Why is it that we can tell human individuals apart? The answer is what ancient Greek literature calls “accidents.”15 An accident is a property that can change without changing what the thing is. For example, the color of a circle can change and it remains a circle. What cannot change is its flowing circumference. Its color is accidental; its circumference is essential. So with human subjects, we can tell Jan, Erik, and Steve apart because they are different sizes and colors; they are in different locations, and so on.

Can the same be said of the Trinity? Is the Father differentiated from the Son by color, size, or location? Certainly not. Just like materiality, accidents have no place in our concept of God. But if God does not have accidents, how are the Father, Son, and Holy Spirit distinguished?

The clue to the orthodox reply is the names Father, Son, and Spirit. What makes the Father the Father is that He begets the Son. What makes the Son the Son is that He is begotten of the Father. The Holy Spirit’s name is obscured in English, but spirit in both Greek and Hebrew also means wind or breath. So we may think of the Spirit as the Breathed One. In other words, the three are distinguished by their relationship to one another.16

This highlights an often neglected feature of Trinitarianism. My impression is that many Christians today think of the Father, Son, and Holy Spirit as simply existing alongside one another, each having existence in Himself. While it is true that the Holy Trinity has always existed, neither the Bible nor the Creed speak of the Son and the Holy Spirit as simply existing from no one. Rather, the Bible, the church fathers, and the Creed teach that the Father has divinity from no one (He is unbegotten), but the Son and the Holy Spirit receive their divinity from the Father. This is what the language of begetting and proceeding means. Just as my only begotten son, David, received his humanity from me, so the Son receives His divinity from the Father. And so the Holy Spirit receives His divinity by spiration from the Father.17

Begotten or spirated, not created. No doubt, if you’ve never heard that the Father gives divinity to the Son and the Spirit, you might wonder if the Son and the Spirit are creatures. In other words, was there a time when God was not yet the Father, and He later created the Son and the Spirit? If this question comes to mind, be assured you are not the first in church history to ask this. Two points should be kept in mind.

First, the Nicene Creed speaks of the Son as “begotten of the Father before all ages.” Drawing on biblical language (e.g., Prov. 8:23; John 17:5; Col. 1:15), the church fathers speak of the Son’s begetting as from eternity. What this means is the Son’s begetting never began. The Father has begotten the Son and spirated the Spirit perpetually from eternity. We might think of it like the relationship between the sun and its rays and heat. If the sun were eternal, then its rays and heat would be eternal also. But the rays and heat would still be caused by the sun: they would be eternally generated. So, the Father eternally begets the Son and spirates the Spirit. He never began doing so.18

Second, Christianity has always insisted that it is because the Father begets the Son and emits the Spirit that they are divine.19 This is most easily demonstrated in the case of the Son. Were I to announce that my wife is pregnant and someone replied, What is it?, they would rightly be perplexed if I replied, I’m hoping for a horse. Even children understand that dog begets dog, human begets human, and so God begets God.20

(3) Not Individually Autonomous. This brings us to a third difference between God and creatures. In the created realm, we think of individuals not only as separate but also as autonomous. Though I have a son, I could have existed without him, as I did for years before his birth. However, Nicene Trinitarianism insists that the divine subjects cannot be isolated in this way. The very identity of the Son of God is rooted in the fact that He is the Son. To identify Him as the Son bids the question, The Son of whom? Likewise, the very identity of the Holy Spirit is that He is Spirit. To identify Him as the Breathed One bids the question, Breathed by whom? And the very identity of the Father is that He is the Father. To identify Him as the Father bids the question, The Father of whom? In other words, unlike human or horse individuals, we cannot think of the Father without also thinking of the Son He begets and the Spirit He spirates. And we cannot think of the Son or the Spirit without the Father who begets and spirates.

This is one of the most important differences between Christianity and the other monotheistic religions. Though Judaism and Islam may lay claim to the God of Abraham who created the cosmos, Christianity alone professes that God has a Son, Light of Light, True God of True God, begotten not made, of the same essence as His Father. And Christianity alone professes that the Holy Spirit is also a divine subject, who with the Father and the Son is worshipped and glorified. But it is this knowledge of God as Father that is revealed to us in these latter days by His Son (Heb. 1:2), and into which we are invited to participate by the Spirit of adoption (Rom. 8:5).

Nathan A. Jacobs (PhD in Historical Theology and in Systematic Theology, Calvin Seminary, Grand Rapids, Michigan) is Visiting Scholar of Philosophy at University of Kentucky.



  1. Some have attempted to resuscitate the heresy of Apollinarianism, according to which Christ does not have a human spirit. See J. P. Moreland and William Lane Craig, Philosophical Foundations for a Christian Worldview (InterVarsity Press, 2003), Part IV, chap. 30. Others deny the Nicene profession that Christ is eternally begotten. E.g., John Feinberg, No One Like Him (Crossway Books, 2001), 492; Robert Reymond, A New Systematic Theology of the Christian Faith, 2nd ed. (Nelson, 1998), 324–30; Wayne Grudem, Systematic Theology (Zondervan, 1994), Appendix 6, 1233–34. Still others espouse the heresy of Sabellianism. See David Bernard, Oneness of God (Word Aflame Press, 1983). In addition, we find Trinitarianisms that, though unintentional in their divergence, are no less problematic. For example, “There is one God, eternally existing and manifesting Himself to us in three Persons — Father, Son and Holy Spirit” (Biola statement of faith). In Nicene terms, God can refer to either God the Father or to the divine nature. The above phrasing is unintelligible by Nicene standards, since the divine nature is not a “He.” Read strictly, the statement appears to be Sabellian — there is one He who reveals Himself through the Persons.
  2. Basil of Caesarea, Epistle, 1.
  3. Tertullian, Against Praxeas, 1; Gregory of Nyssa, Against Eunomius, 1.34.
  4. John of Damascus, On Heresies,
  5. Nathan A. Jacobs, “The Begotten-Not-Made Distinction in the Eastern Pro-Nicenes,” Religious Studies (2018): 9–12.
  6. Throughout, I use individuals or subjects instead of persons because personae is the Latin equivalent of prosopa (faces), which was the position of Sabellius. Individual or subject is a more accurate translation of
  7. Basil of Caesarea, Epistle, See also Gregory of Nazianzus, Orations, 29.13 and Gregory of Nyssa, To Ablabius, passim.
  8. Tertullian, Against Praxeas, 2.
  9. Gregory of Nyssa, To Ablabius, PG 45.117c–25b.
  10. Basil, On the Holy Spirit, 45; Athanasius, Letter to Serapion, 1.28.
  11. John Behr, “Response to Ayres,” Harvard Theological Review 100:2 (2007), 147f.
  12. Gregory of Nyssa, The Great Catechism, 1.
  13. I expound these points in “On ‘Not Three Gods’ — Again,” Modern Theology 24, 3 (2008), 342–44.
  14. Nathan A. Jacobs, “On the Metaphysics of God and Creatures in the Eastern Pro-Nicenes,” Philosophy and Theology 28, 1 (2016): §§II–III. When the Eastern fathers distinguish “material objects” from “immaterial objects,” such as when distinguishing body from soul, this is a statement of relative materiality: in comparison with the body, which has density and mass, the soul is immaterial. The former is what they call “gross matter” (pachu hylikon), while the latter is ethereal and comparatively “immaterial” (aulos). However, even “immaterial” creatures are not truly immaterial in the sense that they have no materiality whatsoever. For these too are finite and spatially located. All creatures, so these fathers argue, have matter by metaphysical necessity.
  15. John of Damascus, The Fount of Knowledge,
  16. I develop this point further in “The Begotten-Not-Made Distinction,” 17–19.
  17. Basil of Caesarea, Epistle, 2; Gregory of Nazianzus, Orations, 29.9.
  18. 18 This analogy is taken from the church fathers: Gregory of Nyssa, Against Eunomius, 2.9; John of Damascus, On the Orthodox Faith, 1.8.
  19. Basil of Caesarea, Epistle, 2; Gregory of Nyssa, Against Eunomius, 1.18.
  20. I offer a complete defense of the begotten-not-made distinction in “The Begotten-Not-Made Distinction,” 1–33.
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