The Swiss theologian Karl Barth was asked by a student during a seminar in the United States, "Dr. Barth, what is the most profound thing you have ever learned in your study of theology?" Barth thought for a moment and then replied, "Jesus loves me, this I know, for the Bible tells me so." The students giggled at his simplistic answer, but their laughter was of a nervous sort as they slowly realized Barth was serious.
Barth gave a simple answer to a question of profundity. In doing so he was calling attention to at least two vitally important notions: (1) That in the simplest Christian truth there resides a profundity that can occupy the minds of the most brilliant people for a lifetime. (2) That even in learned theological sophistication, we never really rise above a child's level of understanding the mysterious depths and riches of the character of God.
John Calvin used another analogy. He said that God speaks to us in a kind of lisping. As parents engage in "baby talk" when addressing their infant children, so God, in order to communicate with us lowly mortals, must condescend to speak to us in lisps.
No human being has the ability to understand God exhaustively. There is a built-in barrier that prohibits a total, comprehensive understanding of God. We are finite creatures; God is an infinite being. Therein lies our problem. How shall the finite comprehend the infinite? Medieval theologians had a phrase that has become a dominant axiom for all subsequent study of theology, "The finite cannot grasp (or contain) the infinite." Nothing is more obvious than that an infinite object cannot be squeezed into a finite space.
This axiom conveys one of the most important doctrines of orthodox Christianity. It is the doctrine of the incomprehensibility of God. The term can be misleading. It may suggest to us that since the finite cannot "grasp" the infinite, that we can know nothing about God. If God is beyond human comprehension, does that not suggest that all of our religious talk is only so much theological babbling and that we are left with, at best, an altar to an unknown God?
This is by no means the intent. The incomprehensibility of God does not mean that we know nothing about God. Rather, it means that our knowledge is partial and limited, falling short of a total or comprehensive knowledge. The knowledge that God gives of Himself through revelation is both real and useful. We can know God to the degree that He chooses to reveal Himself. The finite can "grasp" the infinite, but the finite can never hold the infinite within its grasp. There is always more to God than we apprehend.
The Bible says it this way: "The secret things belong to the LORD our God, but those things which are revealed belong to us and to our children forever" (Deuteronomy 29:29). Martin Luther referred to two aspects of God—the hidden and the revealed. A portion of the divine knowledge remains hidden to our gaze. We work in the light of what God has revealed.