Well presumably the person in question doesn't take the Bible literally, which is quite possible.
I'm not religious myself, but faced with a concept of a Big Bang, in which apparently, everything in an infinite universe was created out of nothing, I can see how believing in a creating deity doesn't seem so odd. Listening to discussions of quantum physics and so on, at my layman's level, it all sounds just as made up as any religion. Perhaps, eventually, it's more provable, but I'm not even sure about that - the best we can say is that the theory fits the evidence - we can't set up an alternative universe to check...
The difference is that one is supported by evidence, and one isn't.