Who would win a war between God and man, and how?

Think of this as a science fiction exercise, not a religious one. Assume there is such an entity as a God who created the universe, but other than that, was subject to the laws of the universe. You can make up any other details about the physical form God takes (and even the metaphysical and psychic form, if you like).

But imagine a war. Humanity wants to take control of the universe (why?). They start a war with God. What happens? Why?