I just think that believing the Big Bang always existing is easier than the god idea. I mean, something made with atoms has GOT to exist, right? As Albert Einstein said that "energy is never wasted, just converted" (or something similar), I'd go with the idea of an extremely (infinitely?) dense matter exploding rather than a non-matter thing churning out extra atoms...
Correct my view if I'm wrong, just thought I'd share.

Therefore, Aliens.