Angus T. Jones
In a YouTube video for Forerunner Chronicles, the Two and a Half Men star not only revealed his involvement with the Seventh-day Adventist ministry, but he also trashed his hit sitcom as "filth" and urged people to stop watching it.
Madonna
Not long after the Material Girl was introduced to Kabbalah in 1996, a group of rabbis called her devotion to Jewish mysticism "sacrilegious." But no matter—Madge remains a dedicated and outspoken follower, one whom the group credits for their sizable celebrity following.
Tim Tebow
The hunky football star is a devout Baptist who frequently talks about his faith during public appearances. And then, of course, there's the phenomenon known as Tebowing, his trademark position in which he goes down on one knee and places a clenched first against his forehead while praying during his games.
Tom Cruise
The movie megastar credits the Church of Scientology for helping him overcome dyslexia, but he came under fire in 2005 when he said that Brooke Shields should have treated her postpartum depression with vitamins instead of Paxil, a position promoted by the L. Ron Hubbard-founded group. Scientology rumors also surrounded the Mission: Impossible star's divorce from Katie Holmes.
Kirk Cameron
A born-again Christian since he was 17 and starring on Growing Pains, the former teen heartthrob's faith became a hot topic earlier this year when he publicly came out against gay marriage and calling homosexuality "destructive to so many of the foundations of civilization."
Richard Gere
The Pretty Woman actor began studying Buddhism in his twenties. He is not only a friend and supporter of the Dalai Lama, but he is also one of Hollywood's most outspoken activists for human rights in Tibet.
Prince
The Purple One gave up performing his more risqué hits after becoming a Jehovah's Witness in 2001.
Kirstie Alley
The former Dancing With the Stars hopeful revealed earlier this month that she credits Scientology with helping her kick a cocaine addiction when she became involved with the church more than 30 years ago.
Stephen Baldwin
The self-described "Jesus Freak" became a born-again Christian after Sept. 11. He outlined his conversion in his 2012 memoir, An Unusual Suspect, and has become the media's go-to guy to comment on Hollywood and religion.
Mel Gibson
The controversial Oscar winner has never shied away from talking about his strict Roman Catholicism, but his faith became headline news when he made The Passion of the Christ, his 2004 film about the last hours of Jesus' life that some critics deemed anti-Semitic. Gibson has also built a chapel on his sprawling Malibu compound and has said he prefers going to all-Latin Masses.
John Travolta & Kelly Preston
The couple has talked openly about being Scientologists, and they were back in the in November 2012 when Preston acknowledged on The Doctors that their late son, Jett, was autistic, a condition the church doesn't recognize because they believe mental and emotional disorders aren't real ailments.