Doctrine of God: Trinity (Part 11): A Plausibility Argument for the Trinity

September 28, 2016

Argument for the Truth of the Doctrine of the Trinity /
Application of the Doctrine of the Trinity

Today we bring our study of the doctrine of the Trinity to a close. You'll remember I have defended a model of the Trinity according to which we think of God as an infinite, unembodied soul but a very special sort of soul, namely a soul so richly endowed with rational faculties that God has three sets of rational faculties each sufficient for personhood so that God is a tri-personal being. I explained last time that this doctrine or model does not feature but neither does it preclude the notion of relations of derivation between the three members of the Trinity. We can think of them as simply three co-equal members of the triune God, or we can add derivative relations if we want to. It seems to me that this is a positive feature the model.

Today I’d like to wrap up by offering a plausibility argument for the truth of the doctrine of the Trinity. The doctrine of the Trinity belongs to revealed theology not natural theology. That is to say you will not be able to prove that God is a tri-personal being through the resources of human reason alone. You might be able to prove that God exists but you wouldn’t know that God is a Trinity. Rather, this is a matter of divine revelation, and one accepts this doctrine based upon God’s self-revelation in Scripture as a tri-personal being: Father, Son, and Holy Spirit. Still, we can ask if there are any arguments that we might give that would support the plausibility of this doctrine that would say, yes, this teaching or doctrine is a credible teaching.

I want to close our discussion of the Trinity with a plausibility argument that has been defended by a number of contemporary Christian philosophers for God’s being a plurality of persons – not simply one person but a plurality of persons. The argument goes like this. By definition God is the greatest conceivable being. That’s St. Anselm’s insight in the ontological argument. If you could conceive of anything greater than God then that would be God. So by definition God is the greatest conceivable being. Now as the greatest conceivable being God must be morally perfect. A perfect being must be morally perfect because to be morally perfect is a great-making property. Love is a moral perfection, and therefore a most perfect being (a greatest conceivable being) must be a loving being. It is better for a person to be loving than to be unloving. So as a morally perfect person God must be essentially loving – a perfectly loving being.

When you think about the nature of love, it belongs to the very nature of love to give oneself away to another. Love reaches out to another person rather than centering wholly in oneself. If you love you are giving yourself away to another. Since God is perfectly loving by his very nature (this belongs to the essence of God) that means that God must be giving himself in love to another. But who is that other? It cannot be any created person because creation is a result of God’s free will, not a result of his nature. It belongs to the very nature of God to be loving, but it doesn't belong to the very nature of God to be creating.[1] So we can imagine a possible world in which God freely chooses to refrain from creating anything at all. There are no creatures at all in such a world and God remains solitary and alone. And yet God would still be essentially loving in such a world because love belongs to his very nature as the most perfect being. So created persons, though they are loved by God, cannot be the explanation for whom God essentially loves. Moreover we know from modern science that created persons have not always existed. The universe has been around for some 14 billion years and human beings have only appeared relatively recently on the scene. Therefore even though God loves created persons, they are not eternal. They have not always existed. But God is eternally loving. He didn’t just begin to be loving some time ago when human beings came into existence. So, again, created persons cannot sufficiently explain or account for God’s being a perfectly loving being.

It therefore follows that the other to whom God’s love is necessarily directed must be internal to God himself. In other words, God is not a single isolated individual person as unitarian forms of theism like Islam hold. Rather God must be a plurality of persons as the Christian doctrine of the Trinity affirms. On a unitarian view of God like Islam, God is a person who does not give himself away essentially in love for another. He is focused essentially only on himself, and therefore he cannot be the most perfect being, the greatest conceivable being. But on the Christian view, God is a triad of persons in eternal, self-giving, love relationships. Because God is essentially loving, the doctrine of the Trinity is more plausible than any unitarian concept of God.

I think this is a very good argument for thinking that God is a plurality of persons. It doesn’t prove that God is three persons, but it does show that there must be a plurality of persons in God to whom God’s love is necessarily directed. Therefore it serves to show the plausibility, at least, I think, of the doctrine of the Trinity.


Student: I was recently reading a book by a Jehovah’s Witness, Greg Stafford, and he briefly tries to give a scriptural argument against this by pointing to passages. His main argument really rests on the whole “love your neighbor as yourself.” So he tries to point to areas in Scripture where it says the idea that you have to love yourself, and so if one can love yourself it is therefore not required for there to be another person.

Dr. Craig: I do think you could have love directed toward yourself but that's what I said. I think that on that view of God, God is entirely self-centered and self-focused. He’s not giving himself away in love. The commandment that he’s quoting is to not simply be self-centered and selfish but to love your neighbor as you love yourself. So I think that verse actually supports the idea that it’s a moral perfection to be directing your love toward others and not to be just a self-centered person but to love another. So I would actually enlist that verse in favor of this argument. It would show that it is a moral perfection to be giving oneself in love to another.

Student: It seems like the argument depends on that at least some creation is outside and not a part of God.

Dr. Craig: Right. This would be the view that there is a possible world in which God exists alone and there isn’t any created world along with him because creation is a free act of God and therefore he could refrain from it.[2] Also, if you think about the argument based on modern science, even if in every world God created humans beings, the fact is human beings haven’t always existed. So God hasn’t been loving human beings for billions and billions of years on the view that human beings are the objects of God’s love. So it still wouldn’t explain how God could be essentially loving rather than just accidentally or contingently loving.

Student: I was listening to Nabeel, and what I thought I heard him say was that on the subject of God’s very nature being love that the Father, Son, and Holy Spirit have always been in a relationship in that love before anything. I just thought it was a beautiful way of knowing where love comes from.

Dr. Craig: Wonderful! That’s exactly the point I am arguing for. I’m saying that that doctrine which is taught by scripture is very credible.

Student: Which is John 1:1?

Dr. Craig: Yes, “In the beginning was the Word, and the Word was with God.”

Student: They were in relationship in love by their very nature.

Dr. Craig: Yes, by God’s very nature he is a triad of loving persons giving themselves to one another.

Student: Even in what you said, it doesn’t prove three persons but it does prove the plausibility of the fact that he is a triune, plural God.

Dr. Craig: You got it. Yes.

Student: I was wondering if perhaps someone could try and get around the fact that humans weren’t created for awhile by saying that God could love things he hadn’t created yet due to his perfect knowledge.

Dr. Craig: That’s not an implausible move though I’m not persuaded that in that case he really is loving that other person because the other person doesn’t exist. I would say he knows that he will love that other person once that person exists, but to say that God is loving that person just because he knows that that person will exist doesn’t seem to me to be a very rich concept of love – of giving yourself to that other person. He will do it but not yet.

Student: So we can simply define that God is relationship.

Dr. Craig: Let’s be careful here. I’m not trying to be technical. God isn’t “a relationship.” He’s a person or is personal – he’s three persons in relationships. So we can say that by definition or by his very essence God is in relationships. He’s not the relationship. He’s the person standing in the relationship.

Student: Well, we can say that God is love and love pertains to relationships so God is relationship which has the quality of love.

Dr. Craig: When we say that God is love, let’s go back to what we talked about when we said the Father is God, the Son of God, and so forth. When you say “God is love” we shouldn’t understand this to be an identity statement. Remember we explained how the word “is” is ambiguous in English. It can be either an “is” of identity or it can be an “is” of predication. When we say God is love I think this is not saying that this is an “is” of identity – that somehow love is God. But it’s an “is” of predication. It is saying that God has the property being love. It is like saying “the chair is red.” You’re not identifying the chair with a color but you’re saying the chair has this property of being red. Similarly “God is love” I would say is a predication about the character of God, and I would make it even stronger and say God is essentially love. He is essentially loving. It belongs to his nature to be loving.

Student: Is it more plausible with God loving humans on the B-theory of time vs. the A-theory of time? Of course, now I’m with you. You entirely convinced me of the A-theory of time. But if you believe the B-theory of time that God is outside of time then humans from his perspective would always be in existence in order to love them. Or is there still an issue with that as well?

Dr. Craig: OK. This class is too-clever-by-half bringing things up.[3] OK, remember on the so-called B-theory or tenseless theory of time, the difference between the past, present, and future is an illusion. In fact, all events in space-time from the Big Bang to the Big Crunch (if there is such a thing) are equally real and time is merely an internal ordering dimension of this four-dimensional space-time manifold or continuum. So the people who exist in 20 BC are no more real or existent than the people who exist in 1965 or the people who exist in 3015. They’re all equally real and God is timeless, outside the four-dimensional space-time, and he loves all of these persons. I think you’re quite right that the argument that I gave based on the fact that persons haven’t always existed is presupposing the A-theory of time, which is that things really do come into being and go out of being, that the difference between past, present, and future is not an illusion – it is objective. But I think you’re quite right. If you go with this view of time and God’s relationship to it then it doesn’t matter how the persons are distributed on the timeline. God will just timelessly love them all. The more important point though would be that this isn’t essential. This space-time doesn’t need to exist. There are possible worlds where God doesn’t create it and therefore just exists alone. Yet he is still loving. So the version of the argument based upon the possibility of God existing alone is more powerful than the argument based simply on temporal creation of persons.

Student: Is it possible that everything that is created is within God, and the B-theory is correct in that all the past exists up until the point present and there’s a future because he truly gives us free will and himself free will to create. He predestines certain things to happen in the future but they have not occurred, but because of his sovereignty he creates them as he goes.

Dr. Craig: OK. You are raising a very interesting and difficult question about God’s relationship to space. Classical theologians not only talked about God’s omnipresence but they also spoke in a very puzzling way about God’s immensity. The doctrine of God’s immensity is the idea that these physical things – space – somehow literally exist in God. God is immense. He fills all of space, and he is present wholly at every point in space. It’s not as though there’s a piece of God that is in this room and then there’s another piece of him in the other room and another piece somewhere else. It’s not like God is spread throughout space like an ether. Rather God is wholly present at every point in space and all of space and creation is somehow in God in this sort of spatial way.

I’m of two minds on this frankly. I tend to think of God’s relationship to space as one of transcendence. He doesn’t exist in space nor does space exist in him, but that God is beyond space and he’s omnipresent in the sense that he is causally active at and cognizant of everything that is happening in space. At every point in space God is there in the sense that he is causally active there and he is cognizant of what’s happening there.

I think that doctrine is plausible in view of the doctrine of creation because this space-time world hasn’t always existed. There was a time when it did not exist in God because it didn’t exist at all. There was just God, and then it came into being. I don’t see why the coming into being of space-time would draw God into space in this way; that it would therefore be literally in God rather than saying God transcends it. He is immanent just in the sense that he’s causally active at and cognizant of every point in space.[4]

Student: That’s very true, but this creation is not the only creation – the first one. If you look at the Improbable Planet, they know a lot know about the big extinction episodes and the immediate abundance of diverse life. This is like a painting of what happened in the past and it is extreme evidence for God creating everything. There is no evolution. Hugh Ross’ new book. I’m just saying you’re right. If the problem of this creation – if it was the only one – would be a death knell to that view.

Dr. Craig: When we’re talking about this space-time manifold, this would encompass any diversity of planets that might have existed in the past or distant reaches of our universe. Those would all be encompassed within this. So even if you say that, say, our earthly existence just occupies a little stretch on the timeline and that prior to that God did other things, other sorts of creations and planets, they are still all within this grand four-dimensional space-time manifold. So I don’t think that kind of creation would suffice to solve the problem that I spoke of – that this thing isn’t necessary and it doesn’t have to exist. There is a state of affairs in the actual world which is just God existing alone without any sort of created order – any angels, any space, any time. There’s just God. Because all of that is a result of his free will.

Student: I have no trouble affirming the Trinity, but it’s easy to feel some sympathy with people who are skeptical. I’m thinking of Dan Brown and maybe Bart Ehrman who say this doctrine was not agreed to for 300 years after Christ. I wonder what your comment would be on why it took that long to sort of disassemble or reverse engineer and come up with the orthodox doctrine of the Trinity? One possible answer would be, I think, that the urgent task of the New Testament – of the Apostles – was to establish the church. And they thought that the second coming was going to happen in their lifetimes or very soon and so they did not feel a need to get into this kind of detail. But I wonder what your comment would be on that.

Dr. Craig: I’m not at all – and I mean this honestly – persuaded at all by this idea that it took 325 years to come up with the doctrine of the Trinity. The reason we went so painstakingly through the biblical material and then each stage of church history was to show how Christians were struggling to understand the idea that the Father is God, the Son is God, the Holy Spirit is God – all of which is affirmed in Scripture – and yet there are not three gods. There’s one God! That’s hard to understand, and it took time and effort to work it out. The central affirmation or the raw material of the Trinity is already in the New Testament. The deity of the Father, the Son, and the Holy Spirit, and yet monotheism. Anybody who affirms that I think is affirming the Trinity, and it just took a while of hard thinking that went through Logos Christology, modalism, and then the challenge of Arianism in order to formulate this idea of three persons in one substance. So I don't find that at all surprising. The point is that the raw materials for the doctrine are right there in the New Testament.


Let me go on to say a word about the application of the doctrine of the Trinity to our lives. There are three points that I wanted to share.

1. The doctrine of the Trinity helps us to order our prayer lives correctly. When the disciples came to Jesus and said to him, Teach us to pray, how did Jesus teach them to pray? He taught them to pray to the Father. “Our Father who art in heaven, hallowed be thy name.” Our prayers are to be directed to the Father.[5] Jesus also said, Whatever you ask in my name I will do it for you. So we are to come to the Father in the person and the authority of the Son. It is because we are in Christ that we dare to approach the throne of the holy God, sinful creatures though we are, to give our request. Then we do it in the power of the Holy Spirit. Remember Paul says in Romans 8, We don’t know how to pray as we ought but the Holy Spirit helps us in our weakness with groans too deep to be uttered, and he who knows the mind of the Spirit then knows what requests we make of him and what we need. The Spirit intercedes for us according to God’s will. So while one might on occasion pray to the Lord Jesus or invoke the presence of the Holy Spirit, the normal model for our prayer life ought to be prayer directed to the Father in the authority and name of the Son and with the power of the Holy Spirit.

2. The Trinity provides a very healthy model of the family and the marriage relationship. Remember we saw that in the Trinity all three of the persons are co-equal. They are all omnipotent, omniscient, morally perfect, eternal, and so forth. They are all partakers of the divine nature and so completely equal. And yet in the economic Trinity these persons take on different roles in the plan of salvation. The Father sends the Son into the world. The Son takes a human nature to himself and dies on the cross as a substitutionary punishment for our sins. The Holy Spirit then works in the place of the Son to establish the church until the Son returns to Earth. So there is a subordinationism (or a submission) of the persons in the economic Trinity. The Son submits to the Father and his will. The Holy Spirit submits to the Son and stands in his place and continues his ministry. So even though all three of the persons are co-equal there is a kind of submission of one person to another within the economic Trinity.

In the same way, in the marriage relationship the husband and the wife are co-equal before God – both made in the image of God. In Galatians 3:28 Paul says, “In Christ there is neither male nor female, slave nor free, but you are all one in Christ Jesus.” So before God’s throne in God’s grace the husband and the wife are co-equal. Similarly the children are equal with the parents insofar as they are in Christ and before God. They are all equal. But in the family unit, for the sake of the functioning of the family, God says that the wife should submit to her husband’s leadership and that the children should submit to their parents and do as they are commanded by their parents. Contrary to what feminists assert, this does not in any way imply inferiority of the wife or of the children for that matter. This is a purely functional submission for the sake of order in the family and doesn’t imply the inferiority of the wife or the inferiority of the children who are all co-equal before God.

3. Finally, I wanted to share with you an email I got this week from a student who listens to the Defenders class and wanted me to share something of the impact that the doctrine of the Trinity had on his own personal spiritual life. So I want to read this testimonial that was sent in by Diego. He said,

As you wrap up the doctrine of the Trinity in Defenders class I was hoping that at the end of your lecture you would share with the class how much of a difference this doctrine can make in a believer’s spiritual life as it did for me by illuminating some of the other attributes of God that we have already discussed.

For me, the Trinity illuminated how, as you have said, creation like salvation is an act of God’s grace.[6] I think that you express this concept well in your article “Divine Timelessness and Personhood”[7] even though you were talking about God’s relationship to time. Still this paragraph just struck me. [Here he quotes a paragraph from that article]

Consider the love relationship between the members of the Trinity! Since intra-Trinitarian relations are not based on physical influence chains or rooted in any material substrata, but are, as it were, purely telepathic, the response of the Son to the Father’s love entails neither change nor temporal separation. Just as we speak metaphorically of two lovers who sit, not speaking a word, gazing into each other’s eyes as “lost in that timeless moment,” so we may speak literally of the timeless mutual love of the Father, Son, and Spirit for one another. . . . Within the fullness of the Godhead itself, the persons of the Father, the Son, and the Holy Spirit enjoy the inter-personal relations afforded by the Trinity which God is. As a Trinity, God is eternally complete, with no need of fellowship with finite persons. It is a marvel of God’s grace and love that He would freely create finite persons and invite them to share in the love and joy of the inner Trinitarian life of God.

What a gift! What a life! When I first read that it was like a switch went off in my head and my heart. I understood what God’s love really meant. How absolutely holy and sacred the Trinity is. His aseity took on a whole new level for me because if he has a life like that why would he need anything else? I was so grateful for God’s power and eternity because that meant he could create creatures like me to enjoy that relationship forever. And his omniscience implied that he would know how to providentially order the world so that I would come to know him. The phrase “How Great Is Our God” finally made sense to me as did the incarnation and the atonement. To think that Christ would suffer the agonies of hell on the cross for my benefit so that I could enter into that relationship free from the sin that separated me from it, it brings tears to my eyes. Wow! What a God he is. This is more than I could ever expect even from the paradigm of goodness. So if you have time, please tell the folks in the class what a difference this doctrine can make in their lives. It sure has made a difference in mine.



I thought that was a wonderful testimony to the practical implications in the spiritual life of this doctrine of the Trinity.


Student: You often hear in Christian circles, “This is a Christ-centered church” or “This is a Christ-centered home,” or a Christ-centered this or that. My feeling based on this study is that while that might be nice shorthand, it is not truly what we ought to be saying. We should be truly a Trinity-centered church and a Trinity-centered home. Is that correct?

Dr. Craig: I resonate with you. I remember when I first read Karl Barth, the German theologian, and his Christ-centered theology it seemed to me that’s a mutated form of Christianity. Christianity is not Christ-centered; it is Trinity-centered. It is these three eternal persons in loving relationships – Father, Son, and Holy Spirit – that is the principal object of our faith. I quite agree with you on that.

Student: We all consider the Trinity one of the foundational aspects of the Christian faith. In light of that, my question is does one need to believe in the Trinity in order to be saved? What is your view on that?

Dr. Craig: I really wrestled with that. When Jan and I were at French language school in France one of the missionaries that was with us in French language school was a member of one of these Oneness Pentecostal groups.[8] It seemed no doubt that he was a Christian. He seemed to have a vital, vibrant relationship with Christ, and yet he didn’t believe in the Trinity. These Oneness Pentecostals believe that Jesus is God – that he’s the Father. That there’s one person that is God, and it’s Jesus! He became incarnate and died on the cross and so forth. It seemed to me that perhaps it is belief in the deity of Christ that is essential to salvation. A person who doesn’t have a good grasp maybe of Christian doctrine or theology might be excused so long as he affirms the deity of Christ for salvation. In Romans 10 Paul says “if you confess with your lips that Jesus is Lord and believe in your heart that God raised him from the dead you will be saved.” That perhaps sets the minimum bar for what you’ve got to belief to be saved. I’m not taking a dogmatic stand on that. I thank God that we don’t have to judge these folks; it is God who will judge them. But it does seem to me that what is really, really essential here would be that affirmation Jesus is Lord – that Jesus is God.

Student: I am going to attempt to break into this relationship theory in my head. Relationship by itself is ever-expanding because you keep on relating. I tried to integrate the ontological Trinity with the functional or economic Trinity in this relationship theory that when God created the heavens and Earth he put everything in the proper relationship for man to live and survive. Jesus’ mission is to bring us into that relationship that he had with the Father. So the work of the Lord and Jesus said is to believe that I come from the Father. That’s the work of the Lord; that we believe that relationship between Jesus and Father and we get into this relationship with Jesus and through him we get into this relationship with the Trinity. So in my mind if I think of God as relationship then we become godly and enter into a relationship mindset.

Dr. Craig: I think I want to affirm what you’re intending to say. I just wish you would put it in other words. Rather than saying that God is a relationship, why can’t you say something like “God is essentially relational” or that “He stands essentially in relationships.” But relationships are things like “to the right of,” “on the top of,” “faster than,” “slower than.” Those are relationships, and God isn’t a relationship. But he is something that stands in relationship – he is persons who stand in a loving, holy relationship to each other. I think you are exactly right. The wonder of salvation is that we become adopted sons of God and are invited into that inner-trinitarian fellowship as adopted children of God. So salvation does consist in coming into that relationship with God. So praise be to him![9]



[1] 5:00

[2] 10:02

[3] 15:04

[4] 20:03

[5] 25:05

[6] 30:06

[7] See (accessed September 30, 2016).

[8] 35:12

[9] Total Running Time: 39:46 (Copyright © 2016 William Lane Craig)