Batman is an Atheist - Big Reveal by DC

In Batman #53 Bruce Wayne serves on a jury. Batman has returned to civilian life after being left at the altar by Catwoman.

As Bruce talks to his fellow jurors he reveals that he no longer believes in God.

Prior to his break up with Catwoman, Bruce said. "God is above us. And he wears a cape." This showed that Bruce's God was his alter ego, Batman. Catwoman crushed all this as not even Batman could stop her from running off at the altar.