The following is a chapter-length excerpt from John Frame’s Concise Systematic Theology, used by permission from P&R Publishers.

GOD, THREE IN ONE

Abstract

God is One, but he exists in three persons, Father, Son, and Holy Spirit. We will explore the biblical basis for this statement and the various discussions about this topic in the early church.

In chapter 2, I said that Scripture presents God to us in three ways: by narrating his actions, by giving us authoritative descriptions of him, and by giving us a glimpse of his inner triune life. We looked at the first two of these all too briefly. In this chapter we will take a glimpse at the Trinity, which corresponds to the lordship attribute of divine presence; for the Trinity indicates that even before the world was made, the Father, Son, and Spirit were present to one another. Remember, though, that Scripture gives us only a glimpse, not a treatise. I think some theologians exaggerate what we know about the Trinity. Much that the Bible teaches about the Trinity is very mysterious, and we must bow in humility as we enter into this holy realm.

We can summarize the doctrine of the Trinity in five assertions: (1) God is one; (2) God is three; (3) the three persons are each fully God; (4) each of the persons is distinct from the others; and (5) the three persons are related eternally as Father, Son, and Holy Spirit. We will look at each of these assertions in turn.

God Is One

We tend to think of the doctrine of the Trinity as the doctrine that God is three persons. But the word triune says not just that God is three persons but also that God is three in one. So the oneness of God, the unity of God, is part of the doctrine of the Trinity.

Scripture, of course, says plainly that God is one. “Hear, O Israel: The Lord our God, the Lord is one” (Deut. 6:4; cf. 32:39). This is important, first, because it is true: there is only one God, only one being worthy of worship, not many, as the Greeks, Egyptians, Babylonians, and Canaanites believed. It is also important because God’s unity is necessary to his lordship. Only one person can be fully in control of the world, speak with ultimate authority, and be the most intimate presence with people. Because there is only one Lord, there can be only one Savior (Isa. 43:11; John 14:6). Salvation, as we have seen, belongs to the Lord (Jonah 2:9).

God Is Three

Of course, the Scriptures also teach that in some mysterious sense God is three. The OT attributes plurality to God, though not with the clarity of the NT. For example, in the OT God’s wisdom is divine, a divine attribute, but it is also distinct from God, a tool he uses in creating the world (Ps. 136:5).

The same holds true for God’s word, his name, his glory, his spirit, and the angel of the Lord (Ps. 33:6; Gen. 31:11–13; Isa. 54:1).

Sometimes the OT even speaks of divine triads:

In all their affliction he was afflicted,
and the angel of his presence saved them;
in his love and in his pity he redeemed them;
he lifted them up and carried them all the days of old.
But they rebelled
and grieved his Holy Spirit;
therefore he turned to be their enemy,
and himself fought against them. (Isa. 63:9–10)

You can find some other triads in Psalm 33:6; Isaiah 48:16; and Haggai 2:5–7. But in the OT this is all quite shadowy and mysterious.

By the NT, however, it is a settled doctrine that three persons are divine: the Father, the Son, and the Holy Spirit. How did this happen? Because before the NT was written, the Son and the Holy Spirit both came into the world. Amazingly, the writers of the NT, mostly Jews, became persuaded that they should worship a man—that the man Jesus was nothing less than God himself. They saw that the Holy Spirit, who came upon the church on Pentecost, was also fully God. So though they continued to confess that God is one (as in 1 Cor. 8:4), they recognized three who were God. Often in the NT we see three divine persons lined up alongside each other:

Go therefore and make disciples of all nations, baptizing them in the name of the Father and of the Son and of the Holy Spirit. (Matt. 28:19)

The grace of the Lord Jesus Christ and the love of God and the fellow- ship of the Holy Spirit be with you all. (2 Cor. 13:14)

(Compare also Matt. 3:16; John 14:16–18; Rom. 1:1–4; 5:1–5; Heb. 2:3–4; 1 Peter 1:2.)

The Three Are God

It is important for us to recognize that the three persons really are equal, because each is fully God. That is fairly obvious in the case of the Father and the Holy Spirit. There have been debates over the deity of Christ. I intend to discuss those in chapter 10. But the conclusion of the Christian church since its inception, and the conclusion of the Bible itself, is that Father, Son, and Spirit are each fully God.

Each of the Persons Is Distinct from the Others

This discussion leaves us with some difficult problems. There is one God, but there are three divine persons. That would appear to be a contradiction, yet God’s Word, the Bible, is never contradictory. So where is the reconciliation?

Some have thought to reconcile these positions by saying that God is really one but only apparently three. Father, Son, and Spirit are just the one God playing three different roles. Sometimes he appears as Father, sometimes as Son, sometimes as Spirit. This position is sometimes called modalism, since it makes the three persons only modes, or ways, in which God exists—not real persons. This view is also called Sabellianism, after Sabellius, one of its early advocates. Today, so-called Oneness Pentecostals teach that Jesus is the only divine person; they call this a Jesus Only position.

The church rejected modalism as a heresy. It is clearly unbiblical, for the three persons enter transactions with one another. Jesus prays to the Father (John 17); the Father speaks from heaven while Jesus is on earth (Matt. 3:17).

The Father and the Son together send the Spirit into the world (John 14:16), and the Spirit bears witness to Jesus. The Spirit is “another” Comforter, not the same as Jesus. The three glorify and honor one another. Here we see three different persons, interacting with one another, conversing as human beings do, not just one person playing three roles.

So the three persons are both one and many, both united and distinct. Look at figure 3.1. The Father is God; the Son is God; the Spirit is God. But the Father is not the Son; the Son is not the Spirit; the Spirit is not the Father.

Even though the three are distinct persons, they are nevertheless inti- mately involved with one another. This mutual involvement is called by the English terms circumcession and coinherence (by the Latin circumincessio and the Greek perichōresis). This means that, first, the Father is in the Son and the Son in him (John 10:38; 14:10–11) and, second, both Father and Son are in the Spirit and the Spirit in them (Rom. 8:9). Notice: it’s not that the Father is the Son and so on but that the Father is in the Son.

When the Spirit comes, inevitably Jesus comes with him and in him (John 14:18). When Jesus comes, we see the Father in him. As he said to Philip,

“Whoever has seen me has seen the Father” (John 14:9). All three persons participate in all the works of God: creation, revelation, redemption, judg- ment. The three glorify one another (John 7:18; 8:50; 16:14; cf. Ps. 110:1).

There are some differences in focus. In redemption, the Father foreknows, the Son sprinkles blood, the Spirit sanctifies (1 Peter 1:2). To generalize, the Father foreordains, the Son accomplishes, and the Spirit applies the work of Christ to the heart. The Father plans, the Son executes, the Spirit applies. Perhaps this is the intra-Trinitarian basis for the three lordship attributes.

The Father is the authority, the Son the controller, the Spirit the presence. Remember that even as the Father is planning, the Son and the Spirit are joyfully cooperating, and the same is true for all the divine tasks.

The Three Persons Are Related Eternally as Father, Son, and Holy Spirit

What we have said already pretty well completes the teaching found in the Bible itself about the Trinity. But you should also know something about the way the church has dealt with questions and problems concerning the Trinity. Make no mistake, the Trinity is a difficult doctrine. The church has had to fight terrible battles over it.

Substance and Persons

First, the church adopted standard terminology to indicate how God is one and how God is three.¹These decisions were made at the Councils of Nicaea (a.d. 325) and Constantinople (a.d. 381). God is one substance, the church declared, and he is three persons. These are philosophical terms, not biblical ones. There is nothing wrong with using terms outside the Bible for theological purposes.

We do it whenever we use English words for the Greek and Hebrew lan- guages of Scripture. Indeed, even the word Trinity is not in the Bible. The work of theology is not just reading through the Scriptures but applying the Scriptures to the questions people ask, applying it to their needs. We’ll discuss this more in chapter 6.

Substance means something like “what he really is.” So the Father really is God, the Son really is God, and the Spirit really is God. Or you can think of the one substance as the “Godness of God.” All three persons have that Godness.²Other terms used as synonyms for substance: essence, being, nature, and their various Greek and Latin equivalents. But all that means is that they are one God, and they are each that one God. In the original Greek text of the Nicene Creed, we read that the three persons are homoousios, that is, of the same substance. Again, that simply means that there is only one God, and each of the three persons is that one God.

Person is a trickier term. Theologians have tried to understand it in differ- ent ways. But after all is said and done, you probably can’t do better than to think of God’s three persons as similar to, analogous to, three human persons.

The church used these terms to show how the heretics were wrong. The Arians said that the Son and Spirit were created beings. On that view the Son and the Father, for example, were not of the same substance. They were not both the one true God. The Sabellians, mentioned earlier, did not believe that God was three persons; they thought he was only one. So the church

used in its creeds the language that God is one substance, three persons. But remember: Scripture gives us a glimpse of the Trinity, not a treatise. We don’t know very clearly what it means for God to be a substance or for

him to be three persons. We don’t even know clearly what substance and person mean when applied to God. We have a rough idea of how these terms apply to things in the creation, but we don’t know what a divine person is and how precisely it differs from the divine substance.

Remember that these terms are just vehicles for biblical content. Some- times we get the idea that when we learn technical theological terms like these we are learning information about God that is not in the Bible, stuff we could learn apart from the Bible alone. But that is certainly not right.

These terms are only attempts to summarize biblical content. They don’t stand on their own. The mystery remains.

Ontological and Economic Trinities

Another common theological distinction, not mentioned explicitly in Scripture, is the distinction between ontological and economic Trinity. These are not two Trinities but the same Trinity viewed in different aspects. Of course, since there is only one God, there is only one Trinity. Ontologi- cal Trinity is the Trinity in itself, as it (or, rather, he) exists apart from the creation, as he would have existed if he had never created anything. In the ontological Trinity there is no subordination among the persons. Father, Son, and Spirit are equal; that is to say, they are equally God, equally divine.

The economic Trinity, however, is the Trinity in relation to the creation. As we saw earlier, the three persons of the Trinity take on a sort of division of labor with regard to creation and redemption: the Father plans, the Son executes, the Spirit applies. In this great drama the Son voluntarily becomes subordinate to the Father. Jesus says he can do nothing of himself but what he sees the Father do (John 5:19). In John 5:30 he says, “I seek not my own will but the will of him who sent me.” The Father has commanded; the Son obeys. Similarly, the Holy Spirit, when Jesus and the Father send him into the world, “will not speak of his own authority, but whatever he hears, he will speak, and he will declare to you the things that are to come” (John 16:13). See the order? The Father sends; Jesus and the Spirit are sent. The Father speaks of himself; the Son and Spirit speak the words the Father has given them to speak.

The three persons are equal, but they take on different jobs in creation and redemption. Some of those jobs involve obedience and subordination. Is that subordination unworthy of God? Not at all. As Jesus taught us in Matthew 20, for example, it is entirely right for great people to be servants, just as he washed the disciples’ feet.

It is important to recognize in any case that the Trinity is both ontological and economic. It is not as if God is really just one person, though he appears as a Trinity to us in the world. That’s what the Sabellians taught. But Trinity is what God really and truly is. Through all eternity, he exists as Father, Son, and Spirit, and he could not exist any other way.

The Eternal Generation, or Begetting, of the Son

The next church-historical issue I wish to discuss is the eternal generation of the Son, sometimes called the eternal begetting. This doctrine attempts to answer the question, how did the Son become the Son?

One biblical answer to that question is found in Luke 1:35, where the angel says to the Virgin Mary, “The Holy Spirit will come upon you, and the power of the Most High will overshadow you; therefore the child to be born will be called holy—the Son of God.” Here the baby Jesus is called the Son of God because of his conception by the Spirit in the womb of the Virgin. So he is the Son by conception, or generation, or begetting—these are all more or less synonymous terms. But Scripture teaches that this conception is not the beginning of his sonship. Before he goes to the cross, Jesus prays, “Father, glorify me in your own presence with the glory that I had with you before the world existed” (John 17:5). Jesus was the Son of his heavenly Father even before he was conceived in Mary’s womb. The theologian asks, If Jesus was already the Son in eternity, was there some kind of generation, or begetting, or conception in eternity that made him the Son? The theologian wonders if Jesus’ begetting in time is parallel to another begetting before time, in eternity.

This question is rather speculative, I think. But Scripture may speak to it, and if it does, we need to hear what it says. Scripture describes Jesus as monogenēs, a term that may mean “only begotten” in some passages, such as John 1:14, 18 and 3:16. Now, there’s some dispute about that. Some Bible scholars think the word means “unique” rather than “only begotten.” But I think the older view is right, so that these passages do say that Jesus was begotten by the Father before the world was made and that he was the only one begotten by the Father, the only begotten Son. So I’m happy to confess, as we do in the Nicene Creed, that Jesus Christ is “the only begotten Son of God, begotten of his Father before all worlds, God of God, Light of Light, very God of very God, begotten, not made, being of one substance with the Father.” The only trouble is that, as with substance and person, I’m not sure what this means. What does it mean for someone to be begotten eternally? When parents beget a son or daughter in this world, the child is younger than the parent. But that’s not the case with Jesus. With Jesus, he and his Father are the same age—eternally existing. Earthly generation requires two parents of opposite sexes, but not eternal generation. When earthly parents

beget a child, the child is weak, helpless, ignorant; but the Son of God in eternity was never weak, helpless, or ignorant. He became that on earth when he was born of a baby. His earthly generation was like that, but his eternal generation was not. So eternal generation is evidently very different from earthly generation.

To be honest, I don’t think that the phrase eternal generation takes us any farther than the name Son. Jesus is the eternal Son. Sons, by definition, are people who have been generated by fathers. But we know nothing about eternal generation, except that it is the generation of a son.

The doctrine of eternal generation does help us, perhaps, to see why it was appropriate for the Son, not the Father, to be generated as a human child in the womb of the Virgin. Perhaps it also gives us a glimpse of why the Son, not the Father, came into the world as the obedient servant.

The Eternal Procession of the Spirit

The next historical issue concerning the Trinity is the eternal procession of the Spirit. This is very similar to the eternal generation of the Son. Just as Jesus was begotten, or generated, in history, so the Spirit proceeded, or was sent forth, from God on many occasions, but especially on the day of Pentecost following the ascension of Jesus. So theologians have asked, is there an eternal procession corresponding to his procession into the world on Pentecost?

The biblical evidence for this doctrine is even more sparse than that for the eternal generation of the Son. People have cited John 15:26 as possibly referring to the Spirit’s procession. Listen to it. Jesus says, “But when the Helper comes, whom I will send to you from the Father, the Spirit of truth, who proceeds from the Father, he will bear witness about me.” The word proceeds here has been taken to refer to eternal procession. I’m not at all sure that’s what it means. I think it much more likely refers to the many times in history that God has sent his Spirit into the world to do his bidding. The Spirit is the one who, over and over again, proceeds from the Father into the created world.

So far as I can see, John 15:26 is the only passage in the Bible that may refer directly to the Spirit’s eternal procession. But we should perhaps say this as well: there must be something about the Spirit’s eternal nature, about his eternal relation to the Father and the Son, that makes it appropriate for

him to be sent rather than to be the sender—to be the one who proceeds. This eternal qualification to be sent we might call his eternal procession. That, I think, is about as much as we can say.

Since this doctrine has so little direct biblical support, I certainly would counsel you not to make an issue out of it. You should know, however, that some people have made a big issue of it, and indeed many still do. The divi- sion between the Western and Eastern churches in 1054 was partly over the detailed formulation of this doctrine. The Eastern churches maintained the original version of the Nicene Creed, which says that the Spirit proceeds from the Father. The Western churches, under the influence of Augustine, added that the Spirit proceeds from both the Father “and the Son” (in Latin, filioque).

Trinitarian Models

The last of these historical issues is that of Trinitarian models. People have tried hard to find illustrations of the Trinity, because, after all, the Trinity is very hard to understand. Illustrations or pictures can make instruction easier. St. Patrick compared the Trinity to an Irish shamrock: one plant, three leaves. Of course, that picture isn’t a very good one. You can tear the shamrock into three pieces but not the Trinity. The Trinity is immaterial, the shamrock material. And the Trinity is three persons, while the shamrock is not even one person.

Other theologians came up with more sophisticated models or illustrations. Basically there are two kinds of Trinitarian models: psychological and social.

The psychological model was developed in great detail by Augustine. Augustine thought the Trinity was like a great mind. In the human mind there is intellect, memory, and will, but the three are one. And when we know ourselves, we are the knower, the known, and the knowledge at the same time. God, of course, has a mind; and, Augustine thought, when God knows himself, his thought of himself is so perfect that that thought itself is a divine being. So the three persons of the Trinity are God as knower, known, and knowledge. This is an interesting model, but it doesn’t do much to account for three persons. In our experience, the known and the knowledge are not persons, nor is the triad memory, will, and knowledge. The psychological model is pretty good in illustrating God’s oneness but not his threeness, his substance but not his persons.

Another model of the Trinity comes from the Cappadocian Fathers of the fourth century, Basil, Gregory of Nazianzen, and Gregory of Nyssa. That has been called the social model, in which Father, Son, and Holy Spirit are three persons much like me and my two sons Justin and Johnny. They relate to one another in love. The interesting thing is that on this social model some have seen the Trinity as a model for human society.

That model is good as far as it goes. Unlike the psychological model, it is interpersonal. But this model doesn’t help us much to see how the three are one God. Augustine began with a single person, a single mind, and then tried to show how complexities in that mind would make it possible to speak of three.

The Cappadocians begin with three but find it hard to show how God is one. So the pendulum goes back and forth between these models. In the early twentieth century, Barth and Rahner, the most prominent Protestant and Roman Catholic theologians, respectively, insisted that God did not have three centers of consciousness. They followed, more or less, the Augustinian

model; Barth even verged on modalism. But in the later twentieth century, under the influence of Moltmann and others, theologians have tended to favor the social model. In my judgment, however, they have not done justice to the fact that God is one God.

I would say that neither model is perfect. We need to find a model that does justice both to God’s oneness (for he is far more one than any of us) and his threeness (for he truly is a society of three). Perhaps better still, we need to recognize the mysteriousness of the Trinity and be satisfied without an adequate pictorial model.

The Trinity and Lordship

Finally, does the doctrine of the Trinity have anything to do with the lord- ship of God, which has been my main theme in this survey? I think it does. Athanasius, bishop of Alexandria, was one of the great heroes of the faith.

A defender of the Trinitarianism of the Nicene Creed, he suffered terrible persecution for his doctrinal stand at the hands of Arian heretics. But he kept going, and eventually, through God’s providence, his position prevailed.

Why did Athanasius fight so courageously and persistently? It wasn’t that he was ready to live or die for philosophical terminology, even the formulation that the Son was “of one substance” with the Father. For him, rather, the important issues were basic and simple: worship and salvation.

Worship. If Jesus the Son of God is only a creature, he said, then we are guilty of idolatry. For Christians had already for nearly four hundred years worshiped Christ as God. He is worthy of worship only if he is equal to the Father, a member of the ontological Trinity.

Salvation. If the Arians were right, Athanasius said, then we are hoping to be saved from sin through a mere creature. Only if Jesus is fully God, a member of the ontological Trinity, can he save us from our sins.

Worship and salvation. In the end, these are matters of lordship, for the Lord is the only one who deserves worship. As Jonah said in his prayer from the belly of the fish, “Salvation belongs to the Lord!” (Jonah 2:9).

Key Terms

• circumcession
• circumincessio
• coinherence
• economic Trinity
• eternal generation
• filioque
• homoousios
• modalism
• monogenēs
• ontological Trinity
• perichōresis
• person
• Sabellianism
• substance
• Trinity
• triune

Study Questions

1. What five biblical assertions can we make about the doctrine of the Trinity?
2. Where does the Bible affirm theonenessof God? Discuss the unity of the Trinity.
3. Where does the Bible reveal the plurality of God? Discuss the diversity of the Trinity.
4. Where do we read about all three persons of the Trinity relating and working together? List two places where Father, Son, and Spirit are either mentioned or discussed together.
5. Show how God’s unity is related to the lordship attributes.
6. Explain Frame’s statement: “The Father plans, the Son executes, the Spirit applies.”
7. Explain person and substance as applied to the Trinity.
8. In describing the tri-unity of God, what does the Greek word perichōresis mean?
9. What do theologians mean by the ontological Trinity and the economic Trinity?
10. Explain what the Greek term monogenēs means (John 1:14, 18; 3:16).
11. What does the doctrine of the eternal generation of the Son help us to understand about Jesus’ relationship to the Father?
12. What does the doctrine of the eternal procession of the Spirit help us to understand about the Spirit’s relationship to the Father and the Son?
13. Describe two of the early church heresies regarding the nature of the Trinity.
14. What are two types of Trinitarian models? What are the strengths and weaknesses of each type?
15. Why did Athanasius believe that worship and salvation were at stake if we misunderstood the doctrine of the Trinity?
16. What is subordinationism? Is there any form of subordinationism that is biblically acceptable?
17. How is the doctrine of the Trinity related to the lordship attributes? To worship and salvation?

Memory Verses

• Isa. 63:9–10: In all their affliction he was afflicted, and the angel of his presence saved them; in his love and in his pity he redeemed them; he lifted them up and carried them all the days of old. But they rebelled and grieved his Holy Spirit; therefore he turned to be their enemy, and himself fought against them.
• Matt. 28:19: Go therefore and make disciples of all nations, baptizing them in the name of the Father and of the Son and of the Holy Spirit.
• 2 Cor. 13:14: The grace of the Lord Jesus Christ and the love of God and the fellowship of the Holy Spirit be with you all.

Resources for Further Study

• Augustine. On the Trinity.
• Bavinck, Herman. BRD, 2:95–334.
• Bray, Gerald. The Doctrine of God. Downers Grove, IL: InterVarsity Press, 1993.
• Frame, John M. DG, chapter 28.
• Gruenler, Royce G. The Trinity in the Gospel of John: A Thematic Commentary on the Fourth Gospel. Grand Rapids: Baker, 1986.
• Poythress, Vern S. “Reforming Ontology and Logic in the Light of the Trinity.” WTJ 57, no. 1 (1995): 187–219. Poythress develops this argument further in his Logic: A God-Centered Approach to the Foundation of Western Thought. Wheaton, IL: Crossway, 2013.
• Reymond, Robert L. Jesus, Divine Messiah. Phillipsburg, NJ: Presbyterian and Reformed, 1990.
• Van Til, Cornelius. An Introduction to Systematic Theology. Nutley, NJ: Presbyterian and Reformed, 1974.
• Warfield, Benjamin B. “The Biblical Doctrine of the Trinity.” In Biblical Doctrines, 22–59. Grand Rapids: Baker, 1981.
• ———. The Lord of Glory. New York: American Tract Society, 1907. Reprint, Grand Rapids: Baker, 1974.
• ———. “The Spirit of God in the OT.” In Biblical and Theological Studies, 127–56. Philadelphia: Presbyterian and Reformed, 1952.

Notes

• 1
  These decisions were made at the Councils of Nicaea (a.d. 325) and Constantinople (a.d. 381).
• 2
  Other terms used as synonyms for substance: essence, being, nature, and their various Greek and Latin equivalents.