The only proof for the existence of God is that without God you couldn't prove anything.
Cornelius Van TilTo admit one's own presuppositions and to point out the presuppositions of others is therefore to maintain that all reasoning is, in the nature of the case, circular reasoning. The starting-point, the method, and the conclusion are always involved in one another.
Cornelius Van TilAgnosticism is epistemologically self-contradictory on its own assumptions because its claim to make no assertion about ultimate reality rests upon a most comprehensive assertion about ultimate reality.
Cornelius Van TilSo, as we have our tea, I propose not only to operate on your heart so as to change your will, but also on your eyes so as to change your outlook. But wait a minute. No, I do not propose to operate at all. I myself cannot do anything of the sort. I am just mildly suggesting that you are perhaps dead, and perhaps blind, leaving you to think the matter over for yourself. If an operation is to be performed it must be performed by God Himself.
Cornelius Van Til