Several things separate the year’s second “conversion therapy” drama, “Boy Erased,” from the first (“The Miseducation of Cameron Post”) is sincerity.

Every character, from the parents of the boy sent to a church boot camp for preaching, teaching, shaming or beating the “gay” out of him, to the people who run “Love in Action,” to the boy (Lucas Hedges) himself, seems genuine about their concerns, their beliefs and their suggested “treatment” for this kid seemingly at the tail end of his “sexually confused” years.

And that’s alarming and occasionally a little funny in Joel Edgerton’s sober and brilliantly acted version of Garrard Conley’s memoir. Unlike “Cameron Post,” there’s little sarcasm and no snark to this story, little eye-rolling about what those in the middle of it all had to know was rank ignorance, even if they didn’t know the word “homophobic” at the time.

Edgerton keeps the camera close to his players who let us see how distressed the Arkansas preacher (Russell Crowe) and his wife (Nicole Kidman) are that their son Jared might be on the verge of becoming a living “abomination” to their faith.

And Hedges (“Manchester by the Sea”) gives us every shade of confused, angry, desperation as the “upstanding and honest son” his father has praised him as from his Baptist pulpit.

“I wish none of this had ever happened,” Jared honestly narrates, “but sometimes I thank God that it did.”

Jared played basketball, cusses on occasion and has a high school girlfriend who is more into him than he is into her. He’s also a preacher’s son, an attentive one. But his first days in college mean steps into a new life. No more girlfriend and jogging with the Fundamentalist hunk down the hall Joe Alwyn make Jared’s gaydar operational.

And that’s what leads his father to “seek the counsel of wiser men,” elders in his faith. The family doctor (Cherry Jones at her Earth Mother best) may be small town Red State, but these testosterone pills she’s asked to prescribe by these not-clued-in old men? She knows those won’t help and tells Jared so, affirming her own faith even as she is laying out the science.

That’s how Jared ends up at the big city church’s gay conversion day camp. Mom stays at a nearby hotel with him, but Jared isn’t to talk about what he goes through, isn’t to share the 12 day or possibly longer “treatment.”

Victor Sykes (Edgerton) insists on it. The young woman and young and old men of The Refuge Program cannot visit the restroom unsupervised, cannot access their phones and take a vow that says “I am using sexuality and sin to fill a God-shaped void in my life.”

The “patients” fill out family trees, hunting for deviant (drugs, booze, same sex attraction, “gang activity”) behavior in their family genetics.

The viewer is allowed to smirk at the suggestion that science and genetics are being used by science deniers to make the case that, as Lady Gaga sang, “I was born this way.”

Jared doesn’t allow himself to smirk, even at the misspellings in the dim-witted and unedited brochures Sykes and his team hand out. Jared is only upset that “this doesn’t seem to be working.”

“This” is some of the silliest (and true to life) “treatment” ever documented. The ethos is “Fake it until you make it.” If you can learn to stand like a man (hands on hips, “thumbs BACKWARD!”), sit like a man (“UNCROSS your legs!”) and hold your own in the batting cage, you’ll form the butch appearance that this crowd craves and it’ll somehow sink in.

Edgerton’s film is split between the fictive present in The Refuge and flashbacks, showing Jared’s traumatic introduction to gay sex, his angry, then tender confrontation with his loving parents — “God help me.” — and the dating life and parental supervision that pointed him towards the path his religion, his family and his ambition laid out for him.

The other patients are the usual collection of “types,” most of them under-developed. The most interesting one is a repeat enrollee at Love in Action, hellbent on changing, but showing up every day with a cut or fresh black eye. Gay bashing? A cruising outing gone wrong?

The staff are also “types,” poorly-educated men ready to use force to keep patients there for a full course of “treatment.” Scariest of these is the ex-addict/ex-con (Flea of the Red Hot Chili Peppers) who sees homosexuality as like any other weakness/addiction.

Edgerton (“The Great Gatsby,” “Black Mass”) makes Sykes earnest to the point of fanatical, but somebody who needs the secrecy he insists on because he lets us see the man’s doubts. He’s making this nonsense up as he goes, and the last thing he wants is scrutiny or second-guessing.

I wish I could get through one movie on this subject or dancing around the edges of it without a suicide attempt. But as melodramatic as that always seems, “It gets better” is a relatively new concept, and tragedies like that were all too common in more primitive times.

We know where this story is going, and the film fails to move along quickly enough to make us forget that destination. But “Boy Erased” all but closes the book on this concept as thoroughly as anything anyone who isn’t irredeemably backward could wish.

And Kidman, playing the subservient wife who is compliant right up to the moment she isn’t, Crowe (impressively buttoned down and conflicted), nervous Edgerton and the always soulful young Hedges make this argument and tell this story with all the warmth and sensitivity you could hope for, and then some.

MPAA Rating: R for sexual content including an assault, some language and brief drug use.

Cast: Lucas Hedges, Nicole Kidman, Russell Crowe and Joel Edgerton

Credits: Written and directed by Joel Edgerton, based on the Garrard Conley memoir. A Focus Features release.

Running time: 1:52