.and if the Bible is in fact true and therefore God has revealed himself to man...how can it be said that he hasn't?
This is supposed to be an argument? Let me turn it around on you - if God has
not revealed himself to man and the Bible is in fact
not true, how can it be said that it is?
People can
say all kinds of things. It's what can be supported that is important.
what criteria would you set in order to believe God's (or a god's) revelation to man?
God existing. That would be a start.