Dan Reynolds addresses the crowd at the 2017 LoveLoud Festival in Orem, Utah. (HBO/HBO)
TV critic

Dan Reynolds is the tall, 30-year-old lead singer of the rock band Imagine Dragons, which, since 2012, has found great success with big, radio-friendly heart-stompers — the sort of ubiquitous hits (“Radioactive,” “Believer,” “Thunder”) that stand in for emotion while one stands in line at Panera.

Reynolds is the seventh of nine kids raised in a devoutly Mormon household in Las Vegas. When the time came, he enthusiastically spent two years as a Church of Jesus Christ of Latter-day Saints missionary, knocking on doors in Nebraska. Just before he found stardom, he met and fell in love with singer-songwriter Aja Volkman. They were married in 2011 in his parents’ backyard, after Volkman agreed to learn and accept LDS doctrines.

“And I felt fine about it,” Volkman says. “Except for the gay rights.” Two of her closest friends, a lesbian couple, took a pass on attending the couple’s wedding.

That understandable snub seems to be the initial trigger for “Believer,” a moving but not entirely satisfying documentary premiering Monday on HBO, in which Reynolds attempts to reconcile his own acceptance of LGBTQ people with his church’s consistent rejection of them.

“I don’t feel a need to denounce Mormonism,” Reynolds says. “I do feel a need as a Mormon to speak out against things that are hurting people.” To spread the message that love is love, Reynolds begins planning an outdoor concert in Orem, Utah (which took place last August).

“Believer” is heartfelt and earnest in all the necessary moments (and beautifully shot), but it’s ultimately about a straight, white, married father of three who wants to have it all ways — to be seen by his worldwide fans as an enlightened and empathetic rock star while remaining faithful to his church. In the film, Reynolds talks about how terrible he felt when his wife’s friends weren’t at the wedding; it’s a guilt he’s carried for years. His tears are real. “If I’m passive, if I just stand back, which I have done, then I feel this burden,” he says. “I feel like I am standing, then, for bigotry.”

As one of the film’s producers, Reynolds has made sure to include scenes where he plays down his role as a catalyst. The last thing people need, he realizes, is a straight celebrity telling them what being gay is all about. His skill for optics is not as naive and aw-shucks as it seems. There’s a lot of calculation going on here.

Not only does the church excommunicate some members for being in gay relationships, it sometimes excommunicates their outspoken straight allies, too — a fact that has Reynolds thinking twice about the potential cost of his cause. He embarks on a listening tour, meeting with people who’ve been hurt by the church’s ostracization. He visits with a couple whose teenage son committed suicide (Utah, according to the film, has a higher-than-average teen suicide rate); he stops by an LGBTQ youth-support center and hears kids talk about their shame and loneliness.

He also connects with another Mormon-raised pop star, Tyler Glenn, the lead singer of Neon Trees, who came out of the closet at the height of his band’s success and suffered for it. Even here, Reynolds finds himself in a state of surplus guilt — the two men share much in common (they easily bond over old “primary hymns” they learned as boys), yet Reynolds was too busy to offer support to Glenn in his hour of crisis. Apology accepted, Glenn agrees to perform at the benefit concert.

“Believer” follows along as the event — called LoveLoud — takes shape, despite initial difficulties with sponsors and ticket sales. The church issues a statement about the concert that gently supports love and acceptance (and in so many words permits LoveLoud attendance), which sends Reynolds over the moon.

At roughly the same time, the brother of Lance Lowry, Reynolds’s hired assistant, commits suicide — not because he was gay, but because he admitted having premarital sex with his girlfriend and thereby received a five-year suspension from Brigham Young University.

After what feels like Reynolds’s zillionth rationale for staying in the church, a rainbow-glittered LoveLoud crowd basks in his beatifically broad message of acceptance. After all his protests about placing himself on a pedestal, there he is, on top of it anyhow.

For all its honesty, something feels slightly off throughout the film; as if we’re seeing only a fraction of the personal turmoil. Reynolds’s anguish is a bit polished and his answers are all easy. “Believer” includes an epilogue in which LDS leadership reaffirms its strong opposition to same-sex relationships; Reynolds goes out on a note of faithful resistance, comparing the experience to his time spent knocking on doors as a missionary. Eventually, he says, someone will answer.

That’s one ending. The other ending I found by Google search: Reynolds and Volkman confirmed in April that they are getting divorced. Proof once more that a camera can be right there in the room and still miss a key part of the story.

Believer (105 minutes) airs Monday at 8 p.m. on HBO.