Fearless as a fatwa and subtle as a Second Coming, "Religulous" is a revelation. For his documentary on the dangers of world religion, comic cultural gadfly Bill Maher traveled from the Holy Land to The Holy Land Experience, questioning true believers of many faiths, mocking all.

"Religulous," produced on the run with Larry Charles of "Borat" fame behind the camera, ridicules Mormonism and Scientology, Islam and Christianity, saving Maher's special wrath for fundamentalism in its many forms.

"Anti-rationalists," Maher calls them. He lumps together George W. Bush, Tom Cruise, con-artist TV preachers, a Senate Democrat and pretty much anybody who bows to Mecca or weeps at crucifixion re-enactments. He outs them, parses their beliefs and frets over the power these folks exercise in our world. The "Apocalypse Now, or at least soon" crowd have their fingers on the Armageddon button, Maher says.

"If there's one thing I hate more than prophecy, it's self-fulfilling prophecy!"

Maher visits Megiddo, Israel, which "end times" enthusiasts embrace as the Revelations-revealed location of Armageddon, the final battle between believers and nonbelievers. He preaches Scientology in London's street-preacher haven of Hyde Park, smokes a joint with an Amsterdam doper from a church of cannabis, is tossed out of the Vatican and Salt Lake City, berated in a Jerusalem mosque and is hugged by Christian truckers in the Trucker's Chapel in Raleigh, N.C.

He seems genuinely charmed by the actor playing Jesus at Orlando's Holy Land Experience theme park. But Maher challenges John Westcott, pastor of the Exchanges ("converted" gays) ministry in Winter Park, Fla.; a Christian Human Genome Project scientist; the founder of the Creation Museum in rural Kentucky; a Muslim Brit rapper who loves his free speech, but hates yours if you criticize the Prophet.

Maher is flip and funny, but also profane and prone to interruption. He can be rude. But he leaves more than one adversary speechless at his command of the Bible, the Quran, the many shared creation and virgin-birth myths that Christianity, Judaism and Islam evolved from.

"Faith means making a virtue out of not thinking," he argues.

He's not quite an equal-opportunity offender. Maher travels to the Wailing Wall but goes awfully easy on the Chosen People (he's half Catholic, half Jewish). He limits himself to religions with apocalyptic leanings.

"Grow up or die," Maher tells the human race. But with the film's mocking tone, inclusion of gay porn and profanity, there's no way he's going to persuade any fundamentalist to repent. Rather, he's reaching out to that sizable segment of humanity that has moved beyond religion. "Speak up," he says, or the folks who claim to hear voices and build their lives around narrow interpretations of bizarre texts will be the doom of us all.