Blake may be converting to Catholicism for his sweetheart -- who's a devout member of the church. A source close to the couple says, "Religion is a big part of her life. This kind of dedication from Blake would show her he's really in it for the long haul. She realized that if she's going to spend the rest of her life with someone, she wants him to share the same values and beliefs. Blake didn't blink when he was asked."
Shelton is reportedly attending the mandatory religious classes in preparing to convert.
Blake has reportedly given up booze for Gwen, which seems much more earth-shattering.
We know that Gwen actually does practice her faith -- paparazzi see her going to church with her kids pretty much every Sunday.