It’s been fascinating to watch the rise and evolution of the faith-based movie over the years, and director Jon Erwin has been a part of that. He has carved out a niche for himself, collaborating with his brother Andrew and focusing on true stories with a musical element, including “I Still Believe,” about Christian music star Jeremy Camp, and “I Can Only Imagine,” about the band MercyMe. The Erwin brothers also co-directed the documentary “The Jesus Music,” which has a direct tie to his latest film, “Jesus Revolution,” which focuses on the same topic — the Jesus movement that took place in Southern California in the late ’60s and early ’70s.

For “Jesus Revolution,” Jon Erwin co-directs with Brent McCorkle, the writer of “I Can Only Imagine,” the pair working from a script by Erwin and Jon Gunn adapted from a book by Greg Laurie and Ellen Vaughn. Laurie is the subject of “Jesus Revolution,” played by Joel Courtney. But the film — part biopic, part period piece depicting a larger movement — juggles three different subjects, including Laurie, Laurie’s mentor, Chuck Smith (Kelsey Grammer) and hippie evangelist Lonnie Frisbee (Jonathan Roumie).

As depicted in “Jesus Revolution,” Smith and Frisbee were huge influences on Laurie, a teen growing up in Newport Beach, California, with a troubled mother (Kimberly Williams- Paisley). When a comely hippie gal, Cathe (Anna Grace Barlow), breaks him out of military school, Greg dabbles in the drug-fueled hippie lifestyle before a few near-death experiences find he and Cathe searching for something more.

At the same time, Chuck is struggling to reconcile his concern over the hippie movement with his daughter Janette’s (Ally Ioannides) rebellion and his dwindling church attendance. When Janette brings home the wandering Lonnie, Chuck realizes that Lonnie’s message is closer to Christ’s than he thought. It also has to help that with his beard, long hair and hand-painted cape, Lonnie looks a lot like the common, white depictions of Jesus. Soon, Chuck’s preaching at Calvary Church is less fire and brimstone and more peace and love.

The storylines converge when Lonnie brings in Greg, who becomes a leader in the burgeoning Jesus movement, while the three men navigate the ups and downs that this growth entails. It’s an interesting enough story, with text at the end of the film claiming that it was the “largest spiritual awakening in America.”

Despite the interesting history, the film itself is a scattered slog, neutered of all the thorny, contradictory details of the real story. Give Lonnie’s Wikipedia page a scan to see just how much material the filmmakers excised from his fascinating life. Though the intent is to focus on Greg, screenwriters Erwin and Gunn can’t pick a lane in their focus, giving us three shallow storylines about three men, with often unnecessary details that bog down the film’s momentum.

“Jesus Revolution” is also a completely uncritical portrait of the Jesus movement. Because this is a faith-based film, it presents the genesis of this “spiritual awakening” and explosion of these churches without examining any of the potential dark sides or ramifications of how this evangelical Christian movement has impacted American culture and politics in the decades since.

MPA rating: PG-13 (for strong drug content involving teens and some thematic elements)

Running time: 2:00

How to watch: In theaters Feb. 24