Well let's say you think of God as some sort of physical being that exists somewhere in the universe or perhaps in some kind of unperceived dimension of space. Let's say we find no evidence of this being within the universe (and it would take us a hell of a long time to explore it all). Then (assuming string theory is correct) we begin to explore other dimensions of space somehow. Let's say we don't find the being. The religious people will still say we haven't explored everywhere yet or concoct some reason to believe God is out there somewhere. Science cannot contend with the simplicity of faith.