When a film about an ex-gay Christian ministry begins with drug-addled homosexual sex, it’s pretty clear where it’s going to end up. Robert Cary’s redemption tale “Save Me,” which opens in the city on Friday, spends a lot of time flirting with a subsection of evangelical Christianity, but from the beginning it’s clear that the relationship isn’t going anywhere.

Robert Desiderio’s screenplay tries to paint its fictional ex-gay ministry in an empathetic light, but the story’s clear rejection of this approach from the onset sucks the emotional development out of his film.

As the opening credits roll, Mr. Cary shifts between scenes of the film’s protagonist, Mark (Chad Allen), engaging in a nearly anonymous tryst, and some rigid, unnaturally restrained churchgoers singing hymns and looking uncomfortable.

Soon we learn that Mark is a strung-out cocaine addict who just wants to be loved. When he ends up in the hospital after yet another overdose, his brother sends him to Genesis House, a Christian-run ministry that helps cure men of “sexual brokenness.” Judith Light plays Gayle, a devout believer who created Genesis House with her former junkie husband, Ted (Stephen Lang), after her gay son overdosed at 17.

Though he rebels at first, Mark quickly takes to Genesis House. Soon he is reciting prayers with gusto, condemning his previous life, and attributing his sobriety to his newfound relationship with God. But one of the men who helped him assimilate at Genesis soon tears him away from the flock. Scott (Robert Gant), a young gay man who came to Genesis in an attempt to salvage a relationship with his dying father, loses his faith when his father renounces him on his deathbed. Gayle, who never believed Scott’s transformation was genuine, also renounces Scott and tries to protect Mark from him. But when Scott decides to leave Genesis, he wants to take Mark along.

“Save Me” rides the coattails of Ang Lee’s “Brokeback Mountain,” sharing not only that film’s central male courtship, but an affinity for nature. Mr. Cary achieves some beautiful shots of the countryside and the attractive young stars of the film in its midst. Partnered with a jangling soundtrack, many shots achieve an alluring masculine aesthetic.

Mr. Allen delivers a strong performance as Mark, and the attraction between the two leads is palpable. But the film’s clear preference for the gay story line undermines its narrative.

In “Save Me,” Christianity is an abuser that victimizes everyone in its path. Be they gay, straight, or aged, the only road to happiness for people in the film is the one that leads away from God. One wouldn’t expect a gay-themed film to hold Christianity in extremely high regard, but a deeper examination of its motives and functions would have lent the story a more authentic air of struggle and discovery. (Just in case there were any doubts about where the film stands on the subject of religion, posters for “Save Me” feature Mr. Allen holding a crucifix to his head as if it were a gun.) Many of the practicing Christians in the film are portrayed as well-intentioned but backward, a patronizing approach that undermines the triumph to which Mr. Cary attempts to build.

Effeminate men populate Genesis House, desperately trying to shed their sexual inclinations and appear heterosexual. Gayle and Ted appear to care for their charges, but they riddle them with absurd strictures that often come across comically and, again, damage of the seriousness of the subject matter. Sitting cross-legged is verboten. There is no wearing of pink. Excessive dancing is discouraged.

An illustrative example of the on-screen absurdity comes after one of the residents of Genesis House frets about meeting the new tenant: “I’m not supposed to worry about things like that — being attractive. Except to women. Praise Jesus and pass the contraceptives!”

But it is Ms. Light, in particular, who misses her mark. The actress has long demonstrated the talent needed to break out of her pop-culture pigeonhole as Angela on TV’s “Who’s the Boss?” But as much as her brittle portrayal of the conflicted Gayle attempts to show the compassionate side of this particularly aggressive branch of Christianity, she cannot bring herself to make a convincing case for her character. Like others in the film, Ms. Light winks through her performance; her inability to find common ground with her character is a fatal performance flaw.

“Save Me” builds a shallow straw man out of “rehabilitating” homosexuals, then spends the rest of its running time pretending to knock it down. The film tries to present a nuanced understanding of Christianity’s failings, but it instead is undone by its own earnestness.