Apparently, you and only you know what goes on inside the mind of God? To answer your question of "why would God create the big bang and evolution?" the answer is I don't have the first idea, and neither do you. The evidence is in favor of both of these ideas, though. I am a scientist so I will NOT claim that both of these are true, they may not be. But as of now, to the best of our ability to understand these questions, these seem to be the best answers. If new evidence is found, I will change this belief.
Big Bang Theory supports creation...