jon14 -- you can find lots of information on the history of religions on the internet, a good starting point might be the Wikipedia entry, or in books like Karen Armstrong's The Case for God.

However given you reject all the evidence for the universe being older than 10,000 years in favour of your interpretation of your version of the Bible (the one with the unicorns if I recall correctly), I'm sure you'll have no problem rejecting any evidence for religions prior to Christianity, or whatever else doesn't match with your personal beliefs.