Doctrine of God: Trinity (Part 1): There Is One God

July 13, 2016


We’ve just finished a very long excursus on natural theology – looking at arguments for and against the existence of God. Before we begin our next section, let’s step back and reconnoiter.

This excursus on natural theology is a subsection of a larger unit that we’ve been covering on the doctrine of God. The first subsection of the doctrine of God that we looked at was the attributes of God in which we discussed God’s nature. Then we temporarily took this excursus on natural theology to look at arguments for God’s existence and against it. Now we want to come to the second subsection of the doctrine of God, and this is on the doctrine of the Trinity.

If I were to ask you here this morning, “How many of you think that God is a person?” probably a number of you would say, “Yes.” Well, technically it is incorrect to say that God is a person. Rather, God is three persons. This is the Christian doctrine of the Trinity. God is personal, yes, but he is not “a” person. This is what serves to distinguish Christianity from other monotheistic faiths like Judaism or Islam which also agree that there is one God who is personal but they think there is only one person who is God. This also serves to distinguish Christianity from various Christian cults and sects like Mormonism (Latter Day Saints) or Jehovah’s Witnesses. You will find inevitably that these sectarian groups get the doctrine of the Trinity wrong – it is almost like a thermometer that you can use to test these different groups to see whether or not they adhere to biblical Christianity.

Unfortunately, the average Christian has little understanding of the doctrine of the Trinity. If he gets into a conversation with a Jehovah’s Witness who comes to his door, I’m afraid that the average Christian will be completely overwhelmed and unable to defend his Trinitarian faith. In fact, if you probe deeply, he probably turns out to be a heretic in the view of the Trinity that he actually espouses. So it is important, I think, that we discuss the doctrine of the Trinity to make sure we accurately understand it.

The doctrine of the Trinity is often obscured by Christians in mystery. Sometimes they will say that the doctrine of the Trinity is logically inconsistent or it is an affront to reason and something that can be held only by faith. It is a mystery. But I think this really does the doctrine a disservice. The doctrine of the Trinity is not even apparently logically contradictory. The doctrine of the Trinity is not the self-contradictory doctrine that three gods are somehow one God, or that three persons are somehow one person. Rather, the doctrine states that there are three persons in the one God. Another way to put it: God is tri-personal.

Often Christians will offer inadequate analogies of the Trinity in order to explicate this doctrine. For example, we are sometimes told that the doctrine of the Trinity is like one man who is a son, a husband, and a father. There is one man but he is a son, he is a husband, he is a father. Unfortunately, that is not an adequate or accurate analogy for the Trinity because in that case you have only one person who is simply playing three roles or has three relationships, but there really is only one person that is there.[1] Another analogy that is often used is that water can be liquid, steam, or ice. Yet it is all H2O. This is perhaps a better analogy because at least here you have one substance – one essence (H2O) – but this could be in the form of a liquid or of steam or of ice. But again the analogy really fails because the water is only successively in those various stages. It can be first liquid, and then if it freezes it turns to ice, or if you boil it it turns to steam. But it is not simultaneous. It is a succession of states in the water.

I think it is better just to avoid these sorts of analogies. They are all, I think, going to be inadequate in the end. It is better to simply say that just as I am a being with one center of self-consciousness whom I call “I”, God is a being who has three centers of self-consciousness each of which can say “I”. Each one has a first-person perspective: I think that I am the Father. I am the Son. I am the Holy Spirit. In the same way that I can say, I am William Craig.

So God is a tri-personal being. He is a being with three centers of self-consciousness in contrast to human persons who are one being with one center of self-consciousness.

The doctrine of the Trinity is a systematic summary of the data of Scripture. Therefore, it doesn’t really matter that the word “Trinity” is not found in the Bible. The important thing is not the word, but rather the concept or the data that this word denominates. Any word could be used to denominate this doctrine so long as the scriptural data are respected and not twisted or bruised in any way. The significant thing is not the word “Trinity.” The significant thing will be the concepts that the Trinity embodies, namely that God is a single tri-personal being.


Student: One way that I heard it explained that I thought made it helpful to me understand what the doctrine is is the way I heard Nabeel Qureshi once describe it. As he talks about it, it is “one what, but three whos.” One being, three persons. He relates a little bit to what you said, but I like the way he explains it where he says if you ask me What am I? I can say, I am a human being. I have a brain, lungs. But that doesn’t answer Who I am? So God is one “what” but three “whos.”[2]

Dr. Craig: Yeah. That is very nice. I’ve not heard it put that way but that does capture the idea of three persons (three “whos”) but one “what” - one being, one substance. That is from a fellow who comes from a monotheistic faith that required a great adjustment and change on his part with a Muslim background.

Student: The defense that a [Jehovah’s Witness] would put forth oftentimes is the Scripture that says “The Father is greater than I.” I know you are about to jump into that. I would hope when you do that you address that.

Dr. Craig: All right. When we get to the deity of Christ we could talk about that. I won’t do that now. We are going to look at the scriptural data here in a moment.

Student: I don’t understand the three “I”s. Are they distinct? Do they communicate with each other? Are they a Venn Diagram? What would make them independent rather than knowledgeable of all three?

Dr. Craig: These are great questions. I want to say yes they are distinct. These are three distinct persons. It is not as though one person can be another person. Persons are distinct. That doesn’t mean they are independent of each other in the sense that one person could exist without the other one because these persons belong to the same being.[3] So it is not as though one of the persons could be extinguished and the other person still exists. So they are not independent, but they are distinct. They are not identical. The Father is not the Son and is not the Holy Spirit. We can say that the Father is not identical to the Son and is not identical to the Holy Spirit. I’m getting way ahead of myself! But when we say that the Father is God, the Son is God, the Holy Spirit is God, we are not making an identity statement. What we are making is a predication of divinity or deity to the Father, the Son, and the Holy Spirit. We’ll talk more about these questions, but the short answer would be that these are distinct persons. We must not try to merge them into one person. They are distinct persons, but they are not independent in that these are the self-conscious persons or consciousnesses of a single being which is God.

Student: But all three are all-knowing?

Dr. Craig: Yes.

Student: So wouldn’t they know each other and wouldn’t that make them non-distinct?

Dr. Craig: They are personally distinct in the sense of identity. Just as you are not Carol or Mary. These are distinct persons. But I think you are quite right in saying that because each one is divine (each one is deity) each one is omniscience, omnipotent, all-loving, and eternal. Each has to share the essential properties of deity which we’ve already looked at.

Student: There would be no distinction between the knowledge of each or the understanding of each then. What is distinct then?

Dr. Craig: Let me nuance it a little bit. Recall when we talked about the attribute of God’s omniscience. We defined omniscience in terms of propositional knowledge. That is to say, in terms of knowledge of all true propositions or facts. We said that a being S is omniscient if and only if (or by definition) for any proposition P, S knows P and does not believe not-P. If those conditions are fulfilled then S is omniscient. This is defined as you notice in terms of propositional knowledge. If you look at your notes from that discussion of omniscience, we pointed out that God is even greater than omniscient because there is also non-propositional knowledge. This would be knowledge of first person statements like “I am the Father.” That is not something that the Son knows. The Son knows that from his perspective “You are the Father.” But he doesn’t think, “I am the Father.” He would be deluded if the Son believed he was the Father. Similarly the Holy Spirit knows “You are the Son. You are the Father.” The Holy Spirit does not believe “I am the Father” or “I am the Son.” I am saying all this because you are asking a very important question about what these persons know and are they different in knowledge. What I want to say is that being omniscient they all have the same propositional knowledge, but being different persons they would have different non-propositional knowledge. Each one has a first person perspective that will yield unique first person non-propositional knowledge. Is that clear? If you don’t remember this, look back at the notes on the divine omniscience section.

Student: You used the word tri-personal to describe the Trinity. I think you have to be really careful with that because I’ve seen error (I can’t remember where I’ve seen it) where the Trinity is referred to as personalities, which would be an error. Each person of the Trinity does have a unique personality but there is a difference between a person and a personality.

Dr. Craig: By personality, you mean something like a psychology or kind of character?[4]

Student: Exactly. Say you assign a personality to the Father and another one with the Son, you end up with Modalism.

Dr. Craig: I am talking about personhood here.

Student: I understand that. It is just that when you used the word tri-personal to describe the Trinity, I was a little concerned about that because I’ve seen this error.

Dr. Craig: Just understand that caveat that one is talking about personhood and not personality.

Student: Since it was brought up the knowledge of the three different beings . . .

Dr. Craig: Three different persons! Not three different beings.

Student: Sure. I’m sorry. Yes, I’m just talking quickly. The three different persons of God. Could you address the Scripture where Jesus talks about the end times and says, Not even the Son knows but only the Father knows? Because that sounds like propositional.

Dr. Craig: We are getting a little ahead of ourselves just like the previous question about The Father is greater than I. Let’s hold those questions until we get to the deity of the Son, then we can raise those issues. OK? Right now we are just introducing the doctrine and want to understand this idea of one God who has three centers of self-consciousness.

Student: Would you define propositional knowledge? Because wouldn’t that not fall under propositional knowledge?

Dr. Craig: It would. Yes, it would. By propositional knowledge, a proposition is the information content of a sentence. So, for example, the sentence “Barack Obama is the President of the United States” has that information content that Barack Obama is the President of the Unites States. But suppose Barack Obama says, “I am the President of the United States.” In that case, he uses a different sentence to express the same proposition that I just expressed when I said, “Barack Obama is the President of the United States.” It has the same information content but the words can be different because he is saying it from a first person perspective and I’m talking from a third person perspective. Another word for true propositions would be “facts” - factual knowledge. Maybe that would help. The idea basically is you take a declarative sentence and then you ask, “What is the information content conveyed by that sentence?” That is propositional content. Propositional knowledge would be knowledge of all true propositions. Again, this is what possible worlds are made of. Remember, a possible world is just a list of all the true propositions that describe reality. That would be similar. A knowledge of all true propositions.

Student: Would it be inappropriate to think of it as one being with three faces? Like in Revelation they talk about faces.

Dr. Craig: This is really interesting, what you just said. Historians have said that you don’t really have in the ancient world prior to these trinitarian debates among the church fathers the concept of personhood. The Greek word for “person” is prosopon and a prosopon was the face mask worn by a Greek actor in the Greek theater. When you wear that mask that would be your face or prosopon. This is the word that came eventually to mean a person. The problem with sticking with that metaphor of the face is that it sounds very much like the doctrine that there is really only one person here – one actor – but he is playing different roles by putting on different masks. And we don’t want to say that.

Student: I’m envisioning a being and, not that he changes masks to depict a character or being, but I am thinking of a being that has three faces simultaneously.

Dr. Craig: All right. That is a metaphor, but I think I understand what you are saying. That does capture the idea of this tri-personal being – three (as it were) faces that stand to each other in “I-thou” relationships and can interact and interact with the world.[5] I just, again, would caution about using metaphors like that because it could sound like a single actor wearing three masks. And you don’t want to say that.

Student: It is just so hard – in a human mind – to try to capture the reality of the Trinity without any help (if you will) in a way to envision it.

Dr. Craig: Yeah, an analogy. I appreciate that. Yes.

Student: Building on what was just said, and coming from a theatrical background, rather than saying one actor with three faces, that actor is portraying three different identities via the masks.

Dr. Craig: But that again wouldn’t be the full doctrine of the Trinity because you still have only one person there.

Student: Yeah, I’m just taking hers a step further for clarification.

Dr. Craig: All right, Although that is not what she wanted to say. Right, a single Shakespearean actor might play a girl or he might play a fellow based upon the costuming and effect of his voice. Those can be different roles. That would be a heretical version of the Trinity because you don’t preserve there the distinction of the persons that we were talking about.

Student: Can I have you draw two diagrams – real simple diagrams? The first is a circle with an arrow coming in and an arrow coming out.

Dr. Craig: OK. Is this what you had in mind?

Student: Yes, exactly. Then the next diagram will be two circles with one arrow in between.

Dr. Craig: OK. Which way does the arrow point?

Student: It doesn't matter. That's right. That's good. Can we say that man is the diagram on the top – that we have to have input and output. Can we say that God is the diagram in the lower end where the Trinity are explained by those three things?

Dr. Craig: Ah. Don't we need to add a third circle?

Student: No. The Holy Spirit is the arrow.

Dr. Craig: Oh! OK. Well! There are theories of the Trinity advocated by certain medieval theologians like Thomas Aquinas in which he thought of the Son and the Holy Spirit as subsistent relations (that is what he called them) in which God stands. He would want to say something like this. This relation here is one of the persons of the Trinity. Now I can't make sense of that myself. I don't see how the idea of a relation can be a person. For me, I just find this completely unhelpful. But you are not out of bounds in talking this way, at least in terms of classical theology.

Student: Can I use an illustration of, say, if we say God the Father is the Creator and all his ways are expounded in words like the Bible or any truthful document or whatever. Then the Son is the receiver of all that and manifestor of all that.

Dr. Craig: The Son wouldn't be the receiver of God's creating activity. Otherwise you make the Son a creature, right? And you don't want to say that. But there is in among the church fathers, as we'll see, this doctrine that somehow the Son is begotten from the Father and not in his human nature but in his divine nature. Among the trinitarian persons, there is this relationship of dependence of the second person on the first. Some of these medieval theologians think of this in terms of a relation where God the Father is like the subject of the relation (an “I”) and then the Son is the object of that relation (“me”). So, for example, when I think about myself – when I think about me – I am both the subject (“I”) but I am also the object of my thought (“me”). I and me![6] There is this type of medieval theology that thinks of the trinitarian persons (at least the Son and the Spirit) as these relations in which the Father stands. Again, to my mind, that doesn't make sense. It isn't what we mean by a person. I don't see how a relation can be a person. But you are not out of bounds so to speak in talking like this because among medieval theologians and Catholic thinkers in particular this type of trinitarian thinking is prevalent.

Student: The reason I wanted you to draw the two diagrams is I wanted to emphasize that men are entity-focused and God is relational-focused. Where I originally wanted you to draw one arrow from the Father to the Son, in essence God is probably demonstrating a relationship more so than an entity so that the Trinity comes in.

Dr. Craig: OK. Well, I won't say any more than what I've already said except that on these views they typically will add a third person who proceeds from the Father and sometimes from the Son. Indeed, sometimes they will say that the Holy Spirit proceeds from the Father by the Son. That is a distinction between Eastern Orthodox thinking and Catholic thinking – whether or not the Holy Spirit proceeds directly from the Father or does he proceed through the Son. Here we are getting into very fine points of church history and Christian doctrine that, I think for now at least, I want to set to one side.

Student: I think I get your point that we can't come up with analogies for the trinitarian God. Maybe stop with coming up with analogies and try to understand who God is. Are we right to say that God is God the Father, God the Son, God the Holy Spirit? Can we say that?

Dr. Craig: Yes, I think that is right.

Student: Then, when you drew up there saying the Father does not equal the Son, the Son does not equal the Holy Spirit, can we say that God equals Father plus Son plus Holy Spirit?

Dr. Craig: I think that that isn't the way that we should speak.

Student: I'm just trying to understand who God is myself.

Dr. Craig: Right. Remember Bill Clinton once remarked that it all depends upon what the meaning of the word “is” is. That was very profound! When you say, He is the king, you could take that to be an identity statement – some person is identical to the king. But suppose you have a co-regency in which, say, there are two kings that are sharing the throne as often happened in history. In that case then it is not an identity statement to say that He is the king. Rather, what you mean by that would be something like He is royal. This second one is not an “is” of identity; it is an “is” of predication. You are predicating a property of that person. You are not saying that he is identical to something. It really is true that it all depends on what the meaning of the word “is” is! Is it an “is” of predication or an “is” of identity? When we say that the Father is God we don't want to say that this is an “is” of identity because since the Son is God as well that would lead to the conclusion that the Father is the Son which we know is false. So this is not a way of making an identity statement. This is an “is” of predication. It means the Father is divine. The Son is divine. Therefore both the Father and the Son are divine.[7] But they are not identity statements anymore than He is royal is an identity statement. That is why I want to explain when we say the Father is God, the Son is God we need to be sure that we understand how we are using the word “is.” Is that helpful?

Student: Sure it is.

Dr. Craig: To someone at least! [laughter] Just think about it. Think about that difference between an identity “is” and an “is” of predication. I didn't intend this to be difficult! It is just that you ask questions! [laughter]

Student: I'm just looking for some advice on how to deal with grandchildren in this area. I was doing a devotional the other day with my grandchildren (they are six years old) and it was Jesus at the Garden of Gethsemane praying. Afterward the grandson asked, “If Jesus is God, why does he have to pray to anyone?” I said, “That's a great question for your grandmother.” [laughter]

Dr. Craig: Oh, come on! You can't pass the buck! I would get them our children's series What is God Like? which is a series of ten illustrated booklets featuring this very endearing cartoon family Brown Bear and Red Goose and their two little children Charity and John. The ninth volume in that series is called God is Three Persons. It is an explanation by Papa Bear to the little children about what the doctrine of the Trinity is all about. This will be an easy and entertaining way to explain this to them, and then will provoke wonderful conversations with your grandchildren about what these issues mean. With respect to your specific question, I think you should say Jesus was not only God, he was also man. So as a man, he depended upon the Father to guide him and to empower him. He worshiped the Father. When Jesus is praying to the Father, this is Jesus as a man praying to God the Father.

Student: If we were to view a trinitarian being that was not God (not perfect in all ways), wouldn't one person of the Trinity be able to disagree with another person of the Trinity?

Dr. Craig: This is one of the objections that sometimes is raised against thinking of the persons of the Trinity as three centers of self-consciousness (as opposed to, say, subsistent relations such as what was discussed before). What if they disagreed with each other? There I think one would simply say that in virtue of their omniscience and their moral perfection, there isn't any possibility of disagreement, because what the Father wills, the Son and the Spirit also will, what the Father knows, the Son and the Spirit know, what the Father loves, the Son and the Spirit also love. So there isn't any possibility of disharmony among the persons of the Trinity precisely because he is the perfect being.


With that, we have introduced the subject that we will be discussing over the next several weeks. I think at this point it would be a good time to simply bring today's lesson to a close. What we will talk about next time will be the scriptural data that undergird the doctrine of the Trinity. We will see that the Scriptures teach both that there is one God and one God alone, but also that there are three distinct persons in the Godhead.[8]



[1] 5:03

[2] See: Nabeel Qureshi, “Turning from Tawhid to the Trinity.” (accessed July 14, 2016).

[3] 10:00

[4] 15:04

[5] 20:08

[6] 25:07

[7] 30:06

[8] Total Running Time: 34:48 (Copyright © 2016 William Lane Craig)