Speaking of the circle used by many philosophies and religions to describe existence, G.K. writes:
They have made many things out of it, and sometimes gone mad about it, especially when as in these eastern sages the circle became a wheel going round and round in their heads. But the point about them is that they all think that existence can be represented by a diagram instead of a drawing; and the rude drawings of the childish myth-makers are a sort of crude and spirited protest against that view. They cannot believe that religion is really not a pattern but a picture. Still less can they believe that it is a picture of something that really exists outside our minds. Sometimes the philosophy paints the disc all black and calls himself a pessimist; sometimes he paints it all white and calls himself an optimist; sometimes he divides it exactly into halves of black and white and calls himself a dualist, like those Persian mystics to whom I wish there were space to do justice.
None of them could understand a thing that began to draw the proportions just as if they were real proportions, disposed in the living fashion which the mathematical draughtsman would call disproportionate. Like the first artist in the cave, it revealed to incredulous eyes the suggestion of a new purpose in what looked like a wildly crooked pattern; he seemed only to be distorting his diagram, when he began for the first time in all the ages to trace the lines of a form–and of a Face.
-G.K. Chesterton, The Everlasting Man, p.153
When your systematic theology always looks like a diagram and almost never a picture of a face, the face of God, the face of Jesus, you can be certain that you are missing the point.