Why do some people believe in God but reject evolution? Why not believe in both?

My girlfriend was home schooled and she has been taught by her very religious parents that evolution is out of the question and that God created all living things as they are. I've tried to explain to her that it's possible to believe in God and evolution simultaneously but she refuses to acknowledge the role evolution has played on this earth and the solid evidence it's left behind. Just because I believe we figured out how living things came to be the way they are today doesn't mean I believe in God any less...wheres the logic in these ideas?