Edward Norton and Ben Stiller are finding religion for roles in “Keeping the Faith.” Norton will play a priest and Stiller will be a rabbi in the romantic comedy, which will begin shooting in May. The film shows what happens when the characters’ childhood crush on a girl reemerges when they’re in their late 20s. The priest is thwarted by his vows of celibacy and the rabbi by the fact that the girl is a not of his faith. The female lead has yet to be cast.