What if God was not a Trinity?

...All this may seem abstract. What are these “persons” in the Trinity? What is this “order”? What in the world is “begetting” or “proceeding”? In order to understand better what the Trinity is all about, it may be helpful to consider a hypothetical different God.* Imagine a self-existent, eternal, transcendent, all-knowing and all-powerful Supreme Being without all the complications of multiple persons - that is, a "one-person" God, a seemingly simpler God, the sort of being we think of most intuitively when the word "God" is spoken. The remarkable qualities of the Trinity can perhaps be seen more clearly when compared to this simpler non-Trinitarian deity.

In such a God there would be no pattern of growth or new things, as there is in the begetting and procession in the Trinity. There would be no love within God’s very being, as there is between the persons of the Trinity. There would be unity, but it would not be the dynamic unity of the stones as they form an arch. It would be the unity of a uniformly painted canvas. In the Trinity, though, we find the unity of a beautiful painting - composed of various shades and tones and textures, yet forming a complete whole.

If, at the bottom of existence, there was one simple and uniform thing and nothing else, there is nothing else in relation to which that thing can be seen. There is no potential - reality cannot grow. But if there is a diverse and complex unity greater than uniformity, facets of reality can reflect each other. That is, if God is One and united, yet at the same time diverse and multifaceted and dynamically interconnected in relation with Himself, things can be seen in relation to one another even at the foundation of existence. The Son is seen in the Father's light, and the Spirit in light of these two. There is a sort of growth in God himself, foreshadowing the growing into being of things other than God: creation is anticipated, as it were, in the Creator himself. Lewis' beautiful description of the dynamic "growth" and creativity within the Trinity says it best and is worth quoting yet again:

…“All things are by Him and for Him. He utters Himself also for His own delight and sees that He is good. He is His own begotten and what proceeds from Him is Himself. Blessed be He!”

*Of course, we must remind ourselves that it is somewhat meaningless to talk about what reality would be if God were different, because God is the basis for all reality – the axiom, the foundation. It is like asking how mathematics would change if two and two did not make four. But even if God could not be other than He is, comparing to the impossible can still serve to deepen our understanding of the actual characteristics of God as He is.