Half a century ago Hollywood was frantically trying to figure out the newly-dominant “youth market.” Since some of that market had recently found Jesus, there was a brief spate of related films: Zefferelli’s hippie-fied St. Francis biopic “Brother Sun, Sister Moon,” adapted stage musicals “Jesus Christ Superstar” and “Godspell,” the Billy Graham-produced “A Time to Run” chief among them. But as the “Jesus Movement” got absorbed into more mainstream institutions, the brief vogue flickered out. 

For a moment there, however, counterculture and Christ had a groovy thing going on, one that promised both salvation for those who’d gone overboard on sex, drugs and rock ’n’ roll, as well as a healthy shakeup of churches that had lost touch with younger generations. Dramatizing that moment is “Jesus Revolution,” an engaging, upbeat new effort from co-directors Jon Erwin (“I Can Only Imagine”) and Brent McCorkle (“Unconditional”), adapted from Greg Laurie’s memoir. 

This inspirational take on a Southern California ministry’s eventually far-reaching impact may not be a definitive representation of some real-life participants’ roles. Nonetheless, it’s one of the most appealing faith-based big-screen entertainments in a while, polished and persuasive without getting too preachy. Kelsey Grammer’s presence may lure some patrons not typically drawn to this kind of attraction, while co-star Jonathan Roumie will help draw those who are — he played J.C. in the well-received Biblical TV series “The Chosen” five years ago. Lionsgate opens the feature on 2,000-plus U.S. screens this Friday, after a more limited Wednesday night “special preview event.” 

After an opening mass-baptism sequence the film returns to about an hour later, the narrative proper begins in 1968 Newport Beach, where fatherless teenager Greg (Joel Courtney) is unhappily enrolled at a local military academy, and no more happy at home with alcoholic mother Charlene (Kimberly Williams-Paisley). He’s more than ready to be liberated from both when his path crosses that of several turned-on public high schoolers, notably Cathe (Anna Grace Barlow), with whom he’s immediately smitten. But the downside of druggy escapism frightens her off before he hits a freaked-out bottom of his own.

Meanwhile, staid pastor Chuck Smith (Grammer) presides over a dwindling congregation. When he expresses prim disapproval of the hippie phenomenon scrutinized on network TV news, his own teen daughter Janette (Ally Ioannides) scoffs such lack of understanding may be “why your church is so empty.” Picking up a hitchhiker one day, she sees a golden opportunity in the form of shaggy Lonnie Frisbee (Roumie). With “Jesus Saves” hand-painted on his poncho, he announces he’s “down from San Francisco spreading the Good News to whoever wants to hear it.” “You’ve got to meet my father,” she grins.

Their meeting is one of “Jesus Revolution’s” high points, as the guileless evangelical positivity of this Jesus-looking (and more importantly, -acting) guy duly wins over the resistant Chuck. Saying his generation is on a “quest for God” — whether they realize it or not — but that “We can only go through doors that are open to us,” Lonnie persuades the older man to invite his kind into his suburban church. That influx ruffles some preexisting parishioners. But the trickle of newcomers, drawn by Lonnie’s charisma and message, soon becomes a flood, with Greg and Cathe prominent among them.

Like a born-again version of Ang Lee’s “Taking Woodstock,” “Jesus Revolution” revisits the “turbulent” ’60s to praise rather than bury, celebrating the essential optimism of its nonconformist youth. Most of this new effort effectively channels that same effervescent spirit, while extending empathy to parental figures struggling to comprehend offspring who’ve suddenly turned alien. It’s to the filmmakers’ credit that there’s at least as much period flavor in scenes of communal hanging out amongst subsidiary characters (some deploying old-school psychedelic visual effects) as in a larger-scale set-piece involving stand-ins for Janis Joplin and Allen Ginsberg. 

The infectious welcome provided by Frisbee’s brand of religious outreach, bolstered by “Jesus music” from seminal Christian rock band Love Song, helped turn Smith’s Calvary Chapel into the incubator for an explosively growing movement. By 1971 it, and the principal players depicted here, landed on the cover of “Time Magazine” (DeVon Franklin plays its investigative reporter). 

But art echoes life here in shunting Lonnie Frisbee out of the picture under questionable pretenses, at which late point some of the air goes out of the movie. We’re left stuck with Smith and Laurie, their boring self-doubts and the underwritten women in their lives, whom Erwin and John Gunn’s screenplay finally gives something to do — they get to tell our remaining heroes how wonderful they are, and how important their mission. Even Frisbee has a torch-passing speech to Greg, which feels labored.

As well it ought, since as detailed in David Di Sabatino’s 2005 documentary “Frisbee: The Life and Death of a Hippie Preacher,” Lonnie didn’t leave the ministries he co-founded so much as he was pushed out. Disinterested in money, by all accounts a truly charismatic figure (some claimed to witness “miracles” he performed, ambiguously portrayed here), he apparently clashed with the more assimilationist values of colleagues who went on to long, high-profile evangelical careers. At least his memory is done justice by Roumie’s persuasively magnetic, touched-by-the-spirit performance.  

Grammer’s sincere turn puts some nuance into the somewhat pat portrayal of Chuck’s evolution from hippie-allergic to hippie advocate, while Courtney and the other younger players do well, even if they seem a mite mature for high schoolers. (For that matter, Roumie looks about twice the age Frisbee was at the time.) And the film does clamber back onto higher ground after a turgid 20 minutes or so by ending with a montage of footage from the era, showing the extent to which so-called “Jesus People” fueled a global phenomenon. That considerably helps close “Jesus Revolution” on the buoyantly proselytizing note Erwin and McCorkle intended. 

Their Kingdom Story Co. production is pleasingly assembled in all departments without seeming over-slick, its throwback vibe nicely conveyed by production designer Aimee Holmberg and Anna Redmon’s costumes — even if Alabama locations must pass for So. Cal. ones. There’s a sufficient soundtrack sprinkling of more-or-less timely archival tracks by Rare Earth, Edwin Star, America, the Doobie Brothers and others amid contributions from latter-day Christian pop artists.