God is a woman?!

A world filled with two religion. Satanism and Christianity. One side worships God and the other Satan. No one has ever heard of someone who weren't leaning towards one side specifically. Enters Angel, a average highschool boy. He doesn't have the best grades however much like everything else. His grades are average. There is nothing unique about him, except for his Atheism. He doesn't believe in either deities and often finds it annoying on how either side continue to try and convince him to join their side. However one day he encountered two girls. God and Satan themselves. He soon realized they were competing in a game, and how he is the missing piece to both the deities.