The Trinity is confusing and confounding to many because almost no one who talks about it remembers to point out that persons are not entities. If you treat persons as things, then the Trinity cannot possibly make any sense. It seems to say that 1 + 1 + 1 = 1. That’s nuts. Yet that’s how almost everyone talks about the Trinity.
I learned (from Whitehead) that persons are not concrete entities, but rather characters of concrete entities. When I much later figured out that the Persons of the Trinity are not different things, but rather characters of a single thing, the logical difficulties that had bedeviled me melted away, and I worried a lot less about it.
The Trinity is like a triangle (equilateral, of course). Each of the Persons is like one of the vertices of the triangle. The vertices are quite different; they are not the same as each other; yet they are all aspects of the same thing. “Aspect” is here deployed advisedly. Taken as a perspective of a mind, of a subject of experience, each of the vertices comprehends the other two, entirely; and in so doing, comprehends their comprehensions of itself. The triangle as a whole then is implicit in each of the vertices. There would not be a triangle without all three; none of the three could be what it is – a vertex of a triangle – without all of the three. All three vertices have the same Nature. But they are not the same as each other; for, were they not disparate, there would be no triangle, and their Natures would be other than they are.
A triangle is like a thing. A vertex of a triangle is like a person of that thing.
It’s trickier to visualize, but we could also say that God is like a sphere, while the Persons of the Trinity are like three mutually orthogonal diameters or circumferences thereof. The sphere analogue is evident in the three dimensional chrismon, in which the stem of the rho is the vertical diameter and the chi furnishes the two horizontal diameters: