Langston Hughes’ 1961 play, which recast the Gospel Christmas story as an African-American musical pageant, forms much of the last act in Kasi Lemmons’ film of the same name. But the cinematic “Black Nativity” isn’t so much a version of Hughes’s piece as a contemporary holiday tale inspired by it. And like most such seasonal parables, it’s heavy-handed and schmaltzy. Even though its heart is in the right place and it boasts a strong cast, it’s a case of preaching—and singing—to the choir.

As rewritten by Lemmons, “Nativity” becomes the story of Langston (pop singer Jacob Latimore), a surly Baltimore teen whose single mother Naimi (Jennifer Hudson) reaches a difficult decision when an eviction notice arrives at their door. Though Christmas is fast approaching, she’ll send the boy to spend the holidays in New York with her estranged parents, whom she hasn’t had contact with since before Langston was born and he’s never even met. He protests, of course, but is soon off on the bus to New York, where he’s robbed by a kid shortly after arrival and winds up in the clink after being wrongly accused of trying to steal a white man’s wallet (he was actually trying to return it, you see).

That’s where he first encounters his granddad Cornell Cobbs (Forest Whitaker), the stern, fastidious pastor of a big Harlem church, who comes to vouch for the boy. Obviously the two don’t hit it off, but Cobbs’s wife Aretha (Angela Bassett) is far more welcoming. Any chance for easy bonding, however, is obstructed by Langston’s yearning to find out who his father was and to return to his mother—a desire that even entices him to lift one of Cornell’s most revered possessions, a sacred relic of the civil rights movement in which he was involved, as a possible source of cash. Luckily the gruff pawn shop operator (Vondie Curtis Hall) recognizes the item and orders the lad to return it. But Langston isn’t done: he aims to buy a gun from the street thug (Tyrese Gibson) he encountered in his jail cell and now finds pushing drugs on a Harlem street corner.

Happily the worst does not happen with that firearm, and the big finale finds Langston dozing off in the front pew of his grandfather’s church during the reverend’s annual “black nativity” service, in which he delivers a joyous sermon while his wife joins the ebullient backup choir. The boy soon experiences a dream that resituates the story of Jesus’ birth in present-day Manhattan, centered on a street couple, Maria and Jo-Jo (Grace Gibson and Luke James), who take on the roles of Mary and Joseph while an angel (Mary J. Blige as a woman who’s earlier saved Langston from being run down by a taxi) hovers nearby. And he awakens to find his mother and father amid the congregation, working out their differences along with Naimi’s long-standing rift with Cornell. Things literally close with a song, a group hug and revelations that can only be swallowed in terms of the conventions of the musical stage, which are extremely liberal in dispensing with logic and plausibility when it comes to unlikely coincidences and sudden changes of heart.

With a cast like this, there are bound to be good moments in the picture Latimore doesn’t exactly make your heart melt with his strident, one-note turn, but Whitaker, as always, is a formidable presence, and Bassett is an appropriately more emotional partner for him. And while Hudson is more often absent than not, she lends her considerable vocal chops to several of the musical numbers, which include both old standards and new material by Raphael Saasiq and Laura Karpman. Gibson is fine as a man with an extremely unlikely secret, while Curtis Hall adds some serious street grit to his few scenes and Blige shows her prowess as a belter even in an unflattering wig. Gibson and James, meanwhile, manage an affecting version of “Silent Night” in one of the scenes in which Lemmons—assisted by cinematographer Anastas Michos, production designer Kristi Zea, art director Douglas Huszti, set decorator Diane Lederman, costume designer Gersha Phillips and choreographer Otis Sallid—opts for more than her usual touch of magic realism—an inclination that gets an even bigger workout in the “blank nativity” dream sequence.

In the end, though, the film ends up feeling like a list of uplifting Christmas messages about lessons learned, confessions made and mistakes righted that are dutifully checked off in a trek to a patently false uplifting finale. And while it offers incidental pleasures along the way, you’re likely to leave it feeling that you’ve experienced this story of familial reconciliation at holiday time better told elsewhere—though probably without such engaging music to accompany it.