Saint Peter Killed God by K.J. Kron

What happens when a priest no longer believes what he preaches? Father Pete acts like he's having a nervous breakdown. He invites his congregation to walk out of mass in protest with him. This fails. No one listens to his sermons, and he's too old and far too embarrassed to start over.

Three days later Father Pete wakes in a hospital suffering from amnesia after attempting suicide. He finds a notebook he doesn't remember filling, with entries referring to himself as Saint Peter. His entries are so outlandish he knows he's insane, but the other patients begin joining him in prayers. They thank him, claiming he's better therapy than any of the doctors.

He can't figure it out. Is he crazy or is it actually his destiny to change the church? The only flock he has now are his fellow patients. Here he begins his journey to retrieve what he has forgotten--those crazy religious beliefs in his notebook entries, which look less and less crazy to him, the details of his attempted suicide, and the real Father Pete.