We have partial knowledge of the fullness of God, not full knowledge of only a part of him. That knowledge will expand, but as with an image in a mirror, it will come into better focus, not be something completely different from what we already know.
From Gerald Bray’s new The Attributes of God: An Introduction, in Short Studies in Systematic Theology, ed. Graham Cole and Oren Martin (Crossway, 2021), 26–29.
The most fundamental attribute of God’s being is its simplicity.
God is “simple” in the sense in which the word is used in chemistry—his nature is not compounded of different elements.
An analogy with water may help us to understand what this means and why it matters. Water is a compound substance made up of hydrogen and oxygen, and it can be separated into its component parts.
God is not a compound. If he were, he could not be the ultimate being. His parts would all be logically prior to him. Presumably there would also have to be some force that produced “god” out of those different parts, and that force would also be a greater being than the resulting “god” is. Such a being does not and cannot exist, and therefore we have to say that God is “simple”—he is what he is, and that is all there is to it.
Divine simplicity means that whatever we say about God applies to the totality of his being. God is not partly invisible or partly immortal. When we meet with God, we meet with him in the fullness of his being, because he cannot be anything less than that. There is much about God that we do not know, but we can be certain that whatever is hidden from our eyes is consistent with what has been revealed to us. Paul told the Corinthians: “Now we see in a mirror dimly, but then face to face. Now I know in part; then I shall know fully” (1 Cor. 13:12). In other words, we have partial knowledge of the fullness of God, not full knowledge of only a part of him. That knowledge will expand, but as with an image in a mirror, it will come into better focus, not be something completely different from what we already know.
