Imagine Dragons frontman Dan Reynolds has been having an eventful week. On Tuesday, his band picked up its fourth career Grammy nomination for Platinum-selling third album, “Evolve.” And today, he’s announcing a Sundance-bound documentary of which he is both an executive producer and subject, “Believer.”

Directed by Don Argott and produced via Live Nation Productions, “Believer” is no typical rock doc. Following up on Imagine Dragons’ August LoveLoud Fest benefit concert in Orem, Utah – which benefited gay rights orgs GLAAD and the Trevor Project, among others – the film takes a broader look at the Church of Jesus Christ of Latter-day Saints’ treatment of LGBTQ members.

“Mormonism is more than just a religion, it’s my culture, it’s my life, it’s my whole family,” Reynolds tells Variety. “So this is something that’s weighed on my heart and mind for a long time, and I’ve seen how destructive and harmful it is to teach our children that being gay is a sin.”

Reynolds was raised Mormon, and experienced his first taste of what he calls religious “shaming” when he was kicked out of Brigham Young University a week before the start of his freshman year, after admitting to premarital sex with his high school girlfriend. He managed to re-enroll a year later, and completed a mission in Nebraska, but he had another rude awakening in the early days of Imagine Dragons when he met his future wife, fellow musician Aja Volkman, at a concert in Los Angeles. Volkman’s two best friends and roommates were gay, and Reynolds recalls they were “pretty upset” to learn that their friend was dating a Mormon, right after the Church’s leadership had thrown its weight behind California’s anti-gay-marriage law Proposition 8.

“They felt like my wife had married into the antithesis of what they had all been fighting for,” Reynolds remembers. He became more and more outspoken about gay rights within the Church – frequently calling attention to the high teenage suicide rate in Utah – and planned the LoveLoud benefit to be held immediately adjacent to BYU’s homebase of Provo. To his surprise, the Church itself issued a statement endorsing the concert, which he calls “a step,” and gives him hope that institutional change is possible.

“If the leaders aren’t going to change their teachings, then it’s the members who have to say, ‘this doesn’t feel right, and we’re not okay with this,’” he says. “A great thing about Mormonism is that they believe in continuing revelation, that God still talks to the prophets, and so they have had changes in the Church. They don’t practice bigamy anymore, like they did in the early days, because God said ‘okay, times are changing, we need to change.’ In the early days of the Church, black people couldn’t join the priesthood, and God came down and said that has to change.”

With “Believer” set to premiere in Utah at Sundance, Reynolds hopes it will continue to force discussion of gay rights within Mormonism on a larger scale. “LoveLoud reached 20,000 people in Utah, which is really small compared to the number of people who need to be reached. I think the reason the film needs to happen is because I feel like this is a way that nobody can turn their heads away.”

Heather Parry, Live Nation president of production, film and television, notes: “It was an honor to help bring Dan’s personal journey to light in ‘Believer,’ and we couldn’t be prouder to help share his story in such an honest and authentic way.”

Reynolds contributed two original songs to the film, and briefly pondered scoring it himself, but ended up delegating those duties to a considerably more experienced hand, Hans Zimmer.

“It’s absolutely crazy,” Reynolds says of getting Zimmer onboard. “I had considered [scoring] it, but I’ve never scored a film. I don’t know how to do that. But Hans Zimmer certainly does, so I figured I’d shoot for the moon and send him an email. ‘Hey Hans, I know you’re probably busy doing the biggest movies of all time, but I have this little tiny documentary…’ And he watched it, and got in contact with me and he said, ‘I have to do this.’

“I just heard the first rough cut of it today, and it was a magical, surreal experience.”