I do not pretend to be able to prove that there is no God. I equally cannot prove that Satan is a fiction. The Christian god may exist; so may the gods of Olympus, or of ancient Egypt, or of Babylon. But no one of these hypotheses is more probable than any other: they lie outside the region of even probable knowledge, and therefore there is no reason to consider any of them.
For God to prove himself on demand, physically, would be a grave disappointment, and the strongest Christians should be considerably grateful that he chooses not to do so. The skeptic endlessly demands proof, yet God refuses to insult the true intelligence of man, the '6th sense', the chief quality, the acumen which distinguishes man from the rest of creation, faith.