Who benefits from gay conversion therapy? Do the parents, who send their queer and questioning kids to be “cured” of their same-sex attractions? Do the young people who are brainwashed into denying the urges they believe to be sinful? Does God? The answer, at least according to Joel Edgerton’s earnestly anti-heteronormative drama “Boy Erased,” appears to be that only the charlatans who run such camps seem to thrive, while everyone else winds up hating themselves.

“Boy Erased” isn’t the first film to share an insider’s perspective of how these camps operate. It’s not even the first film this year: An empowering, female-driven look at such a facility, “The Miseducation of Cameron Post” won the dramatic competition at Sundance. But Edgerton takes a different, more respectful tone to the subject, not outright ridiculing those who believe that homosexuality is a choice, but preaching to the converted all the same — where the “converted” in this case aren’t so-called “ex-gays,” but those who’ve come around to the realization that maybe Christians could stand to evolve as well.

Edgerton, who is Australian, enlists two of the country’s top actors, Nicole Kidman and Russell Crowe, to play a pair of devout Arkansas parents whose faith is challenged when they discover that their son Jared (“Manchester by the Sea” co-star Lucas Hedges) may be gay. Jared himself doesn’t know, which is perhaps the most honest thing the film depicts, dramatizing the way someone raised in a conservative religious community wants nothing more than to be “normal,” frightened by his attraction to other boys and desperate to “fix” whatever is wrong with him. “Boy Erased” is true to that turmoil, telling the story from Jared’s point of view while also treating his parents’ convictions as valid — in their own minds, at least.

Jared’s dad, Marshall, is a Baptist preacher (he also owns a local Ford dealership) who loves to remind his congregation that they are all imperfect people and that only faith can make them whole. One would never guess from the expression on Jared’s face during that sermon what kind of secret shame he might be hiding — in fact, the movie is oddly withholding when it comes to acknowledging him as a sexual being, as if doing so might be manipulative or exploitative: Its lone sex scene features a horrific encounter with a college crush (Joe Alwyn), who brutally rapes Jared, then calls his parents to out him.

When his mom, Nancy, hears the news, a single tear slides down her cheek, and she retreats to her room, where no one will see her mascara run. Marshall is more proactive, calling two church leaders to advise him on what to do. Following their advice, he confronts Jared directly, asking the boy whether he sincerely wants to change and then sending him to conversion camp, a place run by self-anointed therapist Victor Sykes (Edgerton) and a group of men who, we are led to believe, have “overcome” their homosexuality through sheer willpower — plus Flea as an aggressively homophobic drill sergeant type who coaches them on masculinity.

Edgerton never goes as far as “Cameron Post” did in ridiculing gay conversion therapy, intuiting that even a relatively restrained portrayal will make audiences’ blood boil, while a more snide or disrespectful approach might alienate those who believe in such methods. The ultimate goal of Edgerton and his creative collaborators may be to put an end to conversion therapy (end-credits statistics suggest that 700,000 young people have undergone such programs), but that will only happen if concerned parents can be convinced that it does more harm than good — which is why a pair of third-act scenes between Jared and each of his parents have such a powerful impact (bring a hankie).

The trouble with such films — really, with any story set in a rigidly conservative institution, be it a mental hospital (“One Flew Over the Cuckoo’s Nest”), boarding school (“Dead Poets Society”), boot camp (the first half of “Full Metal Jacket”), or conversion program (“The Miseducation of Cameron Post”) — is that they inevitably feel like prison movies, falling back on reductive tropes (like the idea that the authority figures are hypocrites) to make the case that the only solution is to break out. It’s a standard cliché, for instance, that someone winds up being pushed to suicide, thereby serving as a wake-up call to outsiders that there’s a problem. The only question here is who that victim will be.

Real life is more complicated than that, and Edgerton shows an admirable sense of restraint, even when hitting all the usual beats. He includes moments of quiet introspection for the characters and the audience alike, staring at the back of Jared’s head as he presumably tries to pray the gay away (although the movie never answers whether he’s able to reconcile his sexuality with his faith, or else is forced to leave the church ito live his truth). Sykes needn’t be depicted as a villain for his methods to be deemed harmful, and it’s actually more interesting if some of Jared’s camp mates believe in the program. The film might have been stronger if it had given some of the other teens more of a chance to express their views.

Audiences who know Xavier Dolan’s flamboyant reputation as a filmmaker may be surprised to see his near-total transformation into the sullen, emotionally shut-down Jon. Australian online personality Troye Sivan offers the opposite perspective, playing bleached-blond Gary, who offers Jared tips on how to fake his way through the program (he also supplies the soundtrack with two heart-rending ballads, including the terrific original track “Revelation”). Despite his forlorn Charlie Brown-like face and confidence-lacking posture, Hedges looks perhaps the least gay of the group — which is itself an important statement, since communities like those in Arkansas still conflate homosexuality with effeminacy.

If “Cameron Post” served as a useful tool for teenagers, “Boy Erased” feels like its greatest value will be to parents, particularly those with LGBT children of their own — and Crowe and Kidman have seldom been better in their supporting roles. So often, parents view this news as a reflection on themselves, searching to understand their own failings, or else looking for a way to repair the problem. For Garrard Conley, whose memoir inspired Edgerton’s film, sharing his story was the key to repairing things with his parents. Maybe there’s a lesson in there for us. There is for me: My father also lives in Arkansas. Since I came out, we have come to an arrangement: I never talk about my private life, and he never asks — which means, for nearly the last 20 years, he hasn’t really known me. That’s what it means to be a boy erased.