Agnosticism 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.

There are those, of course, who deny that they need any form of authority. They are the popular atheists and agnostics. Such men say that they must be shown by 'reason' whatever they are to accept as true. But the great thinkers among non-Christian men have taken no such position. They know that they cannot cover the whole area of reality with their knowledge.

The only proof for the existence of God is that without God you couldn't prove anything.

Anti-theism presupposes Theism

The Bible is authoritative on everything of which it speaks. Moreover, it speaks of everything.

When man thinks in self-conscious submission to the voluntary revelation of the self-sufficient God, he has therewith the only possible ground of certainty for his knowledge.

The picture of fallen man as given in Scripture is that he knows God but does not want to recognize Him as God.