The doctrine of the Trinity is unique to Christianity and also one of the most difficult to grasp, much less 
explain to others. Hugh Ross in The Creator and the Cosmos offers a most helpful paradigm from science for understanding the Trinity. Ross suggests that the discovery of multiple dimensions creates a context for resolving many apparent paradoxes. String theory posits 10, 11, even 26 possible dimensions. It is understandable that in our four dimensional world, certain concepts will be impregnable. However, by adding multiple dimensions to the equation, God’s triune nature may be less implausible.
It’s been suggested that the doctrine of the Trinity proves Christianity was not concocted by man. Who in their right mind would place something so complex — three distinct beings, eternally existent, co-equal in power, in one God — at the heart of their belief system? But while most apologetics deal with the WHAT and HOW of the Trinity — what is it and how do we defend it — few deal with the WHY. Why does 
God exist in trinity?
In The Unity of the Bible, Daniel P. Fuller offers one of the most intriguing perspectives on the Trinity I’ve come across. While the following hypothesis may not help us explain or defend the doctrine, it can possibly assist in our contemplation of the nature of God.
The outline of the argument goes something like this:
- God is perfect
- God is love
- Because God is perfect He doesn’t need the world — He is perfect in Himself
- But since God is love — and love requires an object or person of its affection — God requires an object / person to share His love
- In order for God to be love and remain perfect — without need of the world — He finds within Himself another Person to love (the Son)
- The Holy Spirit embodies the love that the Father and the Son share; He is the “spirit” of that Relationship, the joy and generation of that ecstatic union
Regarding the Holy Spirit, Scripture is clear that (1) He is a Person and (2) He proceeds from the Father and the Son. Hence, the Westminster Confession makes the following distinction:
III. In the unity of the Godhead there be three Persons of one substance, power, and eternity: God the Father, God the Son, and God the Holy Ghost. The Father is of none, neither begotten nor proceeding; the Son is eternally begotten of the Father; the Holy Ghost eternally proceeding from the Father and the Son.
Notice that, while the Son is “eternally begotten” of the Father, the Holy Spirit is “eternally proceeding from the Father and the Son.” C.S. Lewis puts it this way in Beyond Personality:
The union between the Father and the Son is such a live concrete thing that this union itself is also a Person. I know that’s almost inconceivable, but look at it this way. You know that among human beings, when they get together in a family, or a club, or a trades union, people talk about the “spirit” of that family, or club, or trades union. They talk about its “spirit” because the individual members, when they’re together, do really develop particular ways of talking and behaving which they wouldn’t have if they were apart. It is as if a sort of communal personality came into existence. Of course, it isn’t a real person: it is only rather like a person. But that’s just one of the differences between God and us. What grows out of the joint life of the Father and the Son is a real Person, is in fact the Third of the three Persons who are God.
I like that phrase “communal personality” — the Holy Spirit is the embodiment of the communal 
personality of the Godhead. Fuller points out another interesting aspect of this relationship: “[W]hile we have seen passages in which the Father loves the Son and vice-versa, nowhere does one read of the Father or the Son loving the Holy Spirit, or vice-versa.” Isn’t that fascinating? Why isn’t the Holy Spirit ever described as loving, or being loved by, the Father and the Son, if not for the fact that He has an entirely different relationship with the Father and the Son?
So, in answer to the question Why does God exist in Trinity, we could simply respond: “Because He is love.” Or, to quote Lewis again in Beyond Personality:
The words ‘God is love’ have no real meaning unless God contains at least two Persons. Love is something that one person has for another person. If God was a single person then before the world was made, he was not love.
It’s a compelling assertion about the WHY of the Trinity. Of course, this understanding may not help you advance arguments with your Jehovah’s Witness neighbors, but it’s a provocative meditation concerning the nature of our mighty Triune God.
{ 12 comments… read them below or add one }
This is fascinating. I guess I don’t completely agree with Jesus having to be the “object” of love within God, if I understood the opinion correctly, He only being the “begotten Son” in response to bailing out the human race.
While I agree that the Trinity is hard to explain, I don’t find it difficult to “understand” since God says He is Spirit, Jesus is basically His “physical” representation, and the Holy Ghost is the “essence” of both, all.
Since God is love, only He holds the definition within Himself. He creates as an extension of His love–His angelic hosts long before us. Even planets, fish, animals, greenery, and who knows what all else, came before us.
I don’t think mankind can reason it out as to the whys. He chose to make us in His 3-part image, and we don’t wonder why we are a body, a “soul” or intellect/emotions, and an eternal spirit, one inseparable from the other.
Probably I’m just too simple-minded to get it.
Ditto Nicole’s comment.
I don’t believe God chose the trinity existence with a why – cause effect in mind.
It is simply the nature of the Supreme Being being supreme.(sorry, I couldn’t resist) We, on the other hand, are created in his image, but limited to the confines of the human body.
We have a simpler version inherent in our existence. Mind, body, & soul. Seperate, although the unique sum of the three make you you. But take one away and you are no longer whole.
I’m confused. The logic in Fuller’s 1-6 left my head spinning, particularly #4.
4. But since God is love — and love requires an object or person of its affection — God requires an object / person to share His love.
I guess my question would be, if God is required or obligated to do something, then isn’t he not God? That is, why should God be forced into something?
On second thought, maybe I’m misinterpreting #2. God is love. Does that mean his nature is to love and he could do no other? Or is it that he decided to love?
I guess I have a problem when it seems like there’s a framework or a set of rules that God has to play within. Shouldn’t God be outside of any framework or requirements?
Nicole, by using the term “object” I’m not intending to denigrate Christ but describe the compelling dynamic of love. Love cannot NOT have an object or, maybe the better term, person to lavish.
How exactly that works within the Trinity is a mystery, especially since God is eternal. In other words, the Father did not exist BEFORE the Son. Yet the Son was begotten of the Father. Begetting, as we understand it, implies time. My sons have birthdays. But because Jesus is also eternal, He CANNOT have a birthday — even though He was begotten. Therefore, we are forced to concluded that the Father’s begetting of a Son is completely different than ours. Thus, the Westminster Confession correctly states that “. . .the Son is eternally begotten. . .”
Chris, those are great questions! The idea that God is “required” to do anything is important. Laws must emanate from God’s own nature because if they exist independent of Him, outside of Him, then, as you rightly conclude, it would invalidate His deity. Nothing can exist apart from Him. Therefore, it is God’s own nature (not an external list of laws) that requires Him to act, or not act, accordingly.
Several verses of Scripture tell us God CANNOT do something. Titus 1:2: “[I]n hope of eternal life which God, who cannot lie, promised before time began.†Hebrews 6:18: “[I]t is impossible for God to lie.†Are there laws that keep God from lying? As we established above, they cannot be external laws. But, were God to lie He would cease to be God. So what “requires,” compels or prevents (?) God from lying is His own nature. Therefore, since “God is love,” the laws of love — which is the essence of His own nature — make certain actions impossible.
As with any discussion of the nature of God, human language and understanding fall short. At some point we will reach the end of our mental tether. But hopefully, this answer clarifies more than it confuses.
I didn’t think you intended to “denigrate” Christ, Mike. I guess I view the “eternally begotten Son” as Jesus is also the eternal Savior but in our “time” was not “begotten” until He came to earth to be so, nor was he “our” Savior until He died and was resurrected, yet He is, was, and will always be the same (Hebrews 13:8).
Love is innate in God, but to me that means it is innate in Jesus and the Holy Spirit as well. For me, His creation is the extension/objective of His love.
Chris,
Great comment.
Mike,
Great post. Kudos for having the balls to take a hack at intelligently surveying such a enigmatic theological wonder. Your integration of theology, inquisitiveness, and creativity is refreshing and inspiring.
BTW, I know I’m behind on things but I just read your interview w/ the W.Door. That was great.
I love this … hadn’t thought of it in these ways before … very tangible.
Mike, thanks for bringing up this entire issue. The concept of the trinity truly makes Christianity unique among the world’s religions. As a follower of Reasons to Believe, I agree that Hugh Ross’ discussion of the trinity in the context of God’s extra-dimensional nature is what deepened my faith so much. I am a physician by trade and I had to deal with tough questions from my colleagues. RTB and Hugh Ross’ works helped me answer their tough questions with sound scripture/science correlation. In fact, my current books come out of a desire to share these apologetic paradigms with my readers in a way that is entertaining as well as educational. When we pause and contemplate Moses’ profound question of God’s name and God’s answer we see the eternal, extra dimensional, before time and space context of His great proclamation that the answer to that question is “I Am”! And, Christ echoes this in the Gospels when we see the Holy Spirit descending on the newly baptized Christ in a demonstration of God’s love and approval for His son!
I’m not convinced that we the clay will ever actually know the why the Potter is how He is.
Another thought: gravity affects time. Our perception of reality—and God—is affected by our limited and imperfect frame of reference.
But back to the time thing. If time is a function of creation, then God’s outside time, too.
John 1:1: “In beginning was the Word, and the Word was with God, and the Word was God.” And the chapter goes on to say that that Word is Christ. But someone who prophesies is said to be filled with the Holy Spirit and/or moved by God… so I’m inclined to think that the Three may be like the hand of God: an apt descriptor that’s the closest comparison we can comprehend, but not entirely accurate.
Ross’ book Beyond the Cosmos focuses on multidimensional physics which has implications for a wide variety of “difficult to understand” Christian doctrines. Trinity, free will/predestination, how is God everywhere, hearing everything? etc. One of my personel favorites among sci-apologetics books.
how does the 26 dimensions work exactly?