Sounds like steve here has met his first Christian fideist.
Fideism, or belief in the preminence of faith, is a branch of Christian thought that says it is by faith in God you are redeemed, not just belief in God. For example, I might believe in God, but think he's a vicious psychopath and pray to Satan to protect me from his mindless cruelty. My belief in God isn't in question, but I don't image that attitude would get me into heaven.
Since faith is what is important, God would not provide proof of his existence or it would become unneccesary. If he simultaneously appeared as a 1000 foot face in the clouds over every capital city in the world and announced in a voice of thunder that no you can't eat lobster, wear mixed fibres, or charge interest on loans, a great many people would suddenly find they believe in God, including some who would replace their faith in his existence with certainty of it.
So, say the fideists, God would not prove his existence, since proof denies faith, and faith is the only path to salvation. So in the fideist view the bible is not proof of God, and the events in it can never be shown to have happened (or, in some interpretations, not be shown to be caused by God at least).
I think Douglas Adams famous bit about the babelfish disproving God was based on the fideism of Kierkegaard and its inherent absurdity.