One day a student of mine lingered after class to tell me that he was excited because his family was leaving their church to start a new one. When I asked why they were doing this he informed me that they had to leave their current church because they found out that the new pastor believed in the Trinity. This began a year long process of sitting down to discuss and debate the doctrine at length. He felt that if I used any books or resources other than the Bible it would be cheating because I’d just be quoting authors who agreed with me. He obviously didn’t know about the diversity and debate in early Christianity over this very doctrine. I agreed to his terms and placed myself in a first century mindset with nothing to lean on besides the scriptures themselves. While many would say that it is difficult or impossible for us to comprehend this doctrine, I side with Barth who wrote that, “by God’s revelation we, too, receive and have a part both in His self-knowledge and also in his self-knowability.” We can therefore understand the Trinity to the extent that God has made himself known.
One of the first things I tackled was the Trinitarian formulation in the great commission (Matthew 28:19), pointing to the fact that the Greek word for “name” was singular, implying that Father, Son and Spirit were referred to collectively as one God and not three. Calvin wrote that the three names indicate distinction and not division. All three persons are distinct and different but still the same God. The first declaration in scripture to be reconciled with is Deuteronomy 6 that declares that God is one. Monotheism is a fundamental claim of the people of God in the Old Testament. I quickly found out that my student agreed in one God but not three persons. He also dismissed the passage as being a later addition to the text and insisted that we only baptize in Jesus’ name. Since there are very few passages that mention all three persons and none of them are explicit in explaining the doctrine, I knew I had to build a larger case using logic. The Bible has no explicit doctrine of the Trinity in a single statement. My plan was first to demonstrate Jesus’ divinity, a point we both agreed on, and then show his separateness of personhood from the Father. Plantinga comments that, “[the] NT witness to Christ’s deity is the linchpin of Trinity doctrine. Once Christ’s status [is] clarified as a second divine person, the way [becomes] open for recognition of a third person”. If I could first show Jesus to be God’s divine son, it would be easy to follow with the Holy Spirit.
I began with John 1:1-3. Agreeing that the Word is Jesus from verse 14, I started my argument that Jesus was both with God and was God in the beginning. The verse showed Jesus’ eternal existence as God but also that he was with God. A being cannot be alone and with someone at the same time. The word “with” implies more than one. So while Jesus was and is God, he was also with God or rather God the Father in the beginning. Calvin wrote that, “if the Word were God simply and had not some property peculiar to himself, John could not have said correctly that he had always been with God.” This exposes a fundamental paradox essential to understanding the Trinity; namely that each person of the Trinity has unique properties but is at the same time fully God. C. S. Lewis wrote that, “on a human level one person is one being, and any two persons are two separate beings. On the divine level you still find personalities; but up there you find them combined in new ways which we, who do not live on that level, cannot imagine.” The nature of God’s Trinitarian existence is only paradoxical in the context of our own experience of reality.
There is something uniting that makes the Father and Son one, and also something complimentary that makes them separate. I went on to illustrate some examples of their unity and separateness. Jesus said, “Whoever has seen me has seen the Father,” (John 14:9) and “I and Father are one” (John 10:31). But Jesus also prayed to God as Father (Matthew 6:9) and is described as standing “at the right hand of God” in Acts 7:56. Another important factor in merging these two opposing ideas comes from John 17:21 where Jesus describes that he is in the Father and the Father is in him. This brings up the concept of mutual indwelling, or perichoresis, wherein each person of the Trinity is in some way in the others. It seems impossible for a container to contain a container with contains itself. Once again we are left with a paradox. This to me pointed to the idea that our conception of God cannot be limited to the rules of space and time in the physical universe that we inhabit and try to understand. On a philosophical level, outside the rules of our universe, one can conceive of a reality in which mutual indwelling is possible. So then came the next logical question: If the Father and Son are in each other, then in what ways are the Father and Son the same and in what ways are they different?
I first expressed their difference in terms of their role in history and function in the life of the believer. Jesus is the only member of the trinity to have taken on flesh and is still presently in human form. At a specific point in history Jesus underwent a change in becoming a physical being. Jesus describes God as being spirit (John 4:24). In other words, by my understanding, the Father is a non-physical being. So a key difference between Jesus and the Father is that only one of them is manifested as a being with substance. Someone could try to reconcile this by saying that God as a spirit simply inhabited a body called Jesus. This is in fact what my student argued. A few key problems are exposed here. First is a problem of location. Where is the Father? At Jesus’ baptism the Father’s voice comes from heaven (Mark 1:11) and not from within Jesus himself. Jesus also prayed to the Father who was in heaven. The second problem is that if Jesus was only a body for the father to inhabit then their would be no reason for a resurrection because death would simply be the mode of escape for God’s spirit. However Romans 8:11 describes the Spirit of God (another person) raising Jesus from the dead. A separate person acted upon Jesus raising him up in a glorified body to the right hand of God. This then highlights another difference between each member of the Trinity. Each one acts in history differently and serves a different purpose and function in the story of salvation. The Father sent the Son. The Son gave his life for us. The Spirit raised him up. The Father and Son spent the Spirit to indwell believers.
When looking at the different functions of each person, someone might then assume we are describing three separate gods, which was the accusation of my student. The term person is helpful for describing three persons who act differently. How then are the three persons simultaneously one God? It’s also not enough to simply say that each person is made of the same stuff. Three bottles of water are all made of the same stuff but are not the same bottle. The three persons are also not simply three parts of one God. Each member must be understood as fully God. How is this reconciled? The term applied to God’s sameness is usually substance or ousia. God is three persons but one substance. Substance in English could be misunderstood to mean the “same type of stuff” but it more accurately means that each member of the Trinity is the same being.
Jesus was completely God and completely man. A subscriber of modalism like my student would agree with this statement but say that while Jesus was God he was no longer the Father and not yet the Spirit. The modalist’s concept of God is that He revealed himself as each person progressively through self-revelation. In this view the Father became the Son and then became the Spirit. Tertullian wrote about God as existing in three persons or “faces” to rule out the concept of modalism. In general, the term person falls short to describe the three persons of the Trinity. Augustine of Hippo said, “when you ask ‘Three what?’ human speech labors under a great dearth of words. So we say three persons, not in order to say that precisely, but in order not to be reduced to silence.” We have to have a way to talk about the trinity in terms we understand even if they are insufficient. The terms substance and person can both be misunderstood and misconstrued but they are nonetheless the best terms to discuss the nature of a being so much greater than we can conceive.
Before time itself, the Trinity existed as a perfect community of self-giving love. God so loved us that he intended from the beginning to create us in his image and share with us this love by sending us his Son and giving us his Spirit so that we might participate in his divine community. Each person of the Trinity has played a role in revealing himself to us so that we might know and love him more. After a year of debates and conversations on this topic with my student he still wasn’t convinced, but I felt that I had a much greater handle on the topic overall and could defend it both with scripture and philosophy.
Holy, holy, holy, is the Lord God Almighty,
who was and is and is to come!
Revelation 4:8
Works Cited
Barth, Carl. Church Dogmatics. Edited by G. W. Bromiley and T. F. Torrance. Translated by T. H. L. Parker, W. B. Johnston, Harold Knight and J. L. M. Haire. Vols. II: The Doctrine of God, Part 1. Peabody, Massachusetts: Hendrickson Publishers, Marketing, LLC, 2010.
Calvin, John. Institutes of the Christian Religion. Translated by Henry Beveridge. Peabody, Massachussets: Hendrickson Publishers, Inc., 2011.
Grenz, Stanley J. Theology for the Community of God. Grand Rapids, Michigan: Wm. B. Eerdmans, 2000.
Lewis, CS. Mere Christianity. San Fransisco, CA: HarperCollins, 1980.
Plantinga, Richard J., Thomas R. Thompson, and Matthew D. Lundberg. An Introduction to Christian Theology. New York, New York: Cambridge University Press, 2010.