"Prove to me god doesn't exist"

[Meandering Atheist -J-]

I always liked the way Michael Shermer would tackle this. Instead of proving that he doesn't exist, he demonstrates that people made god up. It seems to follow in a pretty short step that there's no reason to believe in revelation if it comes naturally from man. Maybe next time you could try that approach? Just say you can't prove he doesn't exist, but you have the next best thing.