If the big bang theory is true, OK. But what if the big bang theory is not true? The origin of species like the origin of the universe are puzzles not likely to be solved by our generations. Not until we achieve enlightenment or gather significantly more data than we have to confirm or deny any theoretical model used to understand issues of origin.
What if one of the missing pieces of the puzzle is God? Or what if God is the whole answer to the puzzle? The truth is I do not know if the big bang theory is true, false or somewhere in between. But as this is my birthday and I am thinking about my own origin of which I have significantly more data than I do the big bang, I say keep the discussion away from absolute positions for or against. These may be obscuring the actual solution which may be closer and simpler than we imagine.