Nick Jonas
Nick and the rest of the Jonas Brothers were raised Christian. When Nick and his wife Priyanka Chopra got married, they had a Hindu wedding and a Christian wedding, officiated by Nick's father. He was a former minister in the Assemblies of God Church while the boys were growing up.
Tom Cruise
Actor Tom Cruise is a known Scientologist, claiming, "it's a beautiful religion." He along with celebs like John Travolta, Christopher Reeve, and Will and Jada Pinkett Smith are some of the top practicers. However, most stars who join the church tend to renounce it. Cruise hasn't yet, though.