For the record, I am a near atheist, that strongly doubts God had anything to do with anything, much less guiding evolution. I do however subsribe to the big bang theory. What caused the big bang? I don't have a clue.
From my limited reading, I believe that after the Big Bang was the inflationary phase...
As a bicylist, I *know* this is wrong: Big Bangs (if not resulting from a nail or a thorn in your tire) are the RESULT of an inflationary phase, not the cause :-)
Cheers!
Full Disclosure: Big Bangs can also lead to inflation in the special case of pregnancy--and thus the Big Bang relates to the beginning of life, in refutation of Shubi's earlier posts. ;-)