Haaz Sleiman as Jesus in National Geographic Channel's “Killing Jesus.
” (Kent Eanes/National Geographic Channels)

Lead us not into temptation, but at least allow me the devilish pleasure of scrutinizing HBO’s documentary “Going Clear: Scientology and the Prison of Belief” alongside National Geographic Channel’s dramatic passion play “Killing Jesus.”

Both are airing Sunday night, and both are based on just-the-facts bestsellers that nevertheless aroused concerns and challenges. They are, of course, entirely different programs about entirely different subjects, but “Going Clear” and “Killing Jesus” cannot help but raise compatibly fair questions about the nature of religious belief. Who would ever believe a Jewish carpenter in Roman-controlled ancient Israel could start a faith-based movement by hanging out with prostitutes and tax collectors? Likewise, who would ever believe a writer of pulp science-fiction stories, who exaggerated his war credentials and lived in mortal fear of the Internal Revenue Service, could start a faith-based movement based on self-empowerment techniques taught to him by space aliens?

What qualifies as a religion, anyhow, and what’s it good for?

Jesus, as you might imagine, comes with a much cleaner narrative than L. Ron Hubbard, mostly because there’s so much less to go on and his image has been buffed by a couple millennia of adoration. Time, Newsweek and U.S. News & World Report learned ages ago that you can put an image of Christ on the cover and significantly boost newsstand sales; similarly, Fox News star Bill O’Reilly and history writer Martin Dugard took on the subject of Jesus’s arrest and crucifixion for the third installment in their popular series of books about the deaths of well-known historical figures.

With an efficient and alternately clumsy and eloquent screenplay by Walon Green, “Killing Jesus” does not vary much from the Via Dolorosa. As a result, the lavish NatGeo treatment works a lot better than it did on the channel’s adaptations of O’Reilly’s earlier books, “Killing Lincoln” and “Killing Kennedy.” This story tends to tell itself.

The movie opens with an entertaining, if disturbing, cameo from Kelsey Grammer as a power-paranoid King Herod. Insider info from the three wise men compels Herod to order the mass execution of baby boys in Nazareth (the toddler Jesus escapes with his parents to Egypt) and from there, “Killing Jesus” spends considerable narrative energy explaining the link between the beheading of John the Baptist (because why leave out the dance of Salome?) and the crucifixion of his messiah cousin.

If you can sing all four sides to the “Jesus Christ Superstar” LP by heart, then not only should we become best friends, but you’ll already be hip to the complicated and suggestively flawed Christ that “Killing Jesus” puts forward, as well as the factors that contributed to his demise.

There’s no getting around the shanda-for-the-Jews aspect of this story, either, as the high priests of Jerusalem are scandalized and threatened by Jesus’s words and popularity. As Rome’s designated ruler in Jerusalem, Pontius Pilate (“True Blood’s” Stephen Moyer) is an almost evenhandedly ambivalent player, reluctant to execute Jesus simply because his message is an affront to the leaders of the predominant religion.

Like any movie about the life of Jesus, everything depends on the magnetism of the guy playing him — always a difficult role. In text, Jesus can be a fairly two-dimensional and illogical protagonist, as he willingly walks into the trap laid for him. Before that happens, he lectures those who already follow him and throws a temper tantrum at the temple.

But here I bring good news in the form of a sincere and textured performance from Lebanese actor Haaz Sleiman. If you’ve been puzzled all your life by the fair-haired, blue-eyed Jesuses of Western culture, then Sleiman’s broad-shouldered, Mediterranean messiah is a step in the right direction. He’s a convincing, mysterious and manly Christ, which is a miracle given that he’s working with a spirit-gum beard and one of “The Good Wife’s” missing Alicia Florrick wigs.

He dies (spoiler alert!), but does he rise again? Any movie about Jesus that doesn’t include a flashy resurrection scene tends to irk fervent Christians; the resurrection is key to the faith. But, as with O’Reilly and Dugard’s book, “Killing Jesus” is somewhat ambiguously and beautifully subtle on this point, choosing to end with a scene that metaphorically suggests the beginning of something larger.

The Scientology headquarters in Los Angeles. (HBO)

Director Alex Gibney’s hauntingly effective “Going Clear,” meanwhile, suggests only trouble ahead for the frequently criticized and always strange Church of Scientology, which, the film asserts, now has fewer than 50,000 members but has amassed a billion-dollar treasure chest to fend off its enemies — which it does aggressively.

“Going Clear” arrives amid a clatter of claims and counter-claims. The church says Gibney and HBO failed to allow it a fair say in the film and that basing the documentary on New Yorker writer Lawrence Wright’s 2013 book is a journalistic malfeasance on par with Rolling Stone’s recent debacle with a sensational story about an alleged gang-rape at the University of Virginia. The filmmaker and HBO naturally stand by their work, listing at the end of the film all the people they attempted to contact, from celebrity members on up to Scientology’s leader, David Miscavige.

Both the book and film are aided greatly by the exodus, several years ago, of a number of longtime Scientologists (among them Oscar-winning filmmaker Paul Haggis), some of whom held top positions in the church. They found the courage to leave it and speak out to media (notably the Tampa Bay Times) about Scientology’s darker operations, which include allegations of abuse, spying and prison-like conditions for believers whose perceived crises of faith threatened the church’s fixation on secrecy and loyalty.

“Going Clear’s” only small problem is how much of Wright’s book it tries to cram into two hours. A digression into actor Tom Cruise’s ascendance as the church’s ideal celebrity Christ-figure, second (well, third) only to Miscavige and late Scientology founder L. Ron Hubbard, could have been its own fascinating documentary.

The explosive new documentary "Going Clear: Scientology and the Prison of Belief," debuted at the Sundance Film Festival on January 25. In these three clips from the film, former members describe joining the controversial religion and their attempts to escape. (   The Washington Post)

A long primer on Hubbard (who died in 1986 without officially designating a successor) and the early days of his pop-psychology “Dianetics” success is a necessary foundation to understanding how the church grew and evolved. Hubbard’s ex-wife was the first to doubt his appeal: “I felt that he was stealing from people and hoodwinking them,” she wrote. “He began to believe . . . that he really was this God figure.” There’s also a fascinating side trip into Scientology’s decades-long battle with the IRS, the only government agency that has the power to decide, for tax purposes, whether or not a shared belief system qualifies as an actual religion. (The IRS granted Scientology tax-exempt status in 1993, according to the film, locking in Miscavige’s power and vastly expanding the fortune of the church, which stood to owe a billion or so in back taxes.)

Former members frankly discuss the moments they began to doubt what they were being told. Those who reach “OTIII” status are allowed to read Hubbard’s handwritten secrets locked away in a briefcase, a moment in which they discover that the key to it all is an intergalactic overlord named Xenu and that Earth was once an exile planet and is now rife with escaped “thetan” spirits dwelling within modern humans. Haggis recalls wondering whether this moment was itself a sort of insanity test: “Maybe if you believe it, they kick you out. . . . I’m down for the self-help stuff [and] okay, maybe I can be ‘clear’ and get rid of the negative emotions, but [WTF] is this!?”

It’s here that many viewers without a dog in this hunt might be inclined to side with Scientology. People believe all sorts of unbelievable things, such as (for just some examples that I grew up with) the parting of the Red Sea, virgin birth, walking on water, transubstantiation and resurrection. What’s the harm in letting Scientologists search for inner thetans when the religion offers a salve to our modern-day culture of rejection and self-doubt, particularly in Hollywood? Given that Scientology is a relatively young church (despite its trillion-year prequel story), is its current PR crisis comparable to Christianity’s early history in the lion’s den?

That’s where “Going Clear” begins to make its strongest case, that Scientology is a religion founded on fear, make-believe and tax evasion, spending too much time and effort intimidating its dissenters and critics, often ending in family estrangement and other forms of abuse.

The film also effectively harnesses the weirdness of its findings. Old clips of Commodore Hubbard on his yacht with his seafaring followers are enhanced with kooky synthesizers and theremin solos; more recent clips of Miscavige’s showy and pompous rallies for believers seem to adhere to the aesthetics of fascism. All the while, a viewer will keep asking himself: What do these folks really believe in?

“If you go to a Jew or Christian or a Muslim and ask them what do you believe, they can basically describe the most important part of their religion in a minute or two,” says journalist Tony Ortega, whose work has involved deep dives into the church’s finances. “Well, what does a Scientologist believe? You need to be in Scientology for seven or eight years and in for a couple hundred thousand dollars before you finally learn the back story of Xenu. . . . If you were told that on day one, how many people would join? If they were upfront about it, I’d have more respect for them.”

Going Clear (two hours) premieres Sunday at 8 p.m. on HBO.

Killing Jesus (three hours) premieres Sunday at 8 p.m. on National Geographic Channel.