Did you know that there’s a new family-audience feature film that implies that God nuked Japan because one plucky American moppet dared to dream? That’s no exaggeration. In the summer of 1945, the kid stands on a California dock, points his fingers magician-style out at the Pacific horizon and screams a series of prayerful “Arrgghh!”s in his efforts to perform some war-ending miracle. He’s trying to move heaven and earth to get his father home from a P.O.W. camp.

The kid prays and arrgghhs until the filmmakers, gauche and monstrous, cue up a jubilant “This Little Light of Mine” for the payoff to a gag you will have dreaded since learning the film is called Little Boy and that “Little Boy” is its small-fry hero’s nickname. One morning his neighbors are dancing in the street, and the headline in the local paper credits “Little Boy” as the de facto catalyst for the end of the war. That God — always eager to smite foreign cities if you just believe!

Examinations of faith on film don’t have to be noxious. This spring, a welcome restoration of René Clément’s 1952 jewel Forbidden Games will hit screens. That’s an honest film about children’s faith and trauma in World War II, one about the ways that ritual can help us persevere through loss. But Little Boy is fitted for an era in which finding the faith that might sustain just isn’t uplifting enough — despite the fact that that’s the only thing faith can actually do.

Instead, the faith of Pepper Busbee (Jakob Salvati) is a superpower: This comic-book devotee hears the verse from Matthew in which Jesus proclaims that with faith the size of a mustard seed, a believer can move a mountain. Pepper takes that literally, in the newish evangelical tradition, and sets himself to the task of believing with such force and purity that God will end the war and spirit his father home. At a magic show at the local movie house, Pepper is tricked into believing he has some talent for telekinesis; a couple of reels later, wouldn’t you know it, he’s in the town square, taunted by bullies and his brother, London (David Henrie), terrible people who don’t believe what the shrimpiest kid they know is saying about belief and mustard seeds. His brother gets the where’s-your-messiah-now? routine: London points to a nearby mountain and dares the Little Boy to move it. Pepper points to it, arrgghhs gratingly, and then, after much juiced-up tension, the movie stages an earthquake.

Little Boy attempts to maintain some plausible deniability regarding its miracles. That earth-shaking could be a coincidence! It even labors to convince us it isn’t claiming that Heaven sanctioned the leveling of Hiroshima and Nagasaki: Pepper dreams he walks through a bombed-out city, and he sees a family shaped from ash — a reminder that the deaths of millions isn’t Easter-morning sunny. But Little Boy only feints toward rationality.

The acting’s often good, but the director, Alejandro Monteverde, seems restless despite having co-written the script. He finds many excuses to mount fantasy sequences that seem to come from movies he’d prefer to be making: a pastiche of cliffhanger serials; a miserable kung-fu showdown; a CGI disaster flick.

I’m going to spoil the ending. The kid who never doubted is vindicated. The father, long presumed dead, comes home, well after his own funeral, just as the family he’s left is learning to persevere — and just moments after his bereaved wife (the great Emily Watson, bless her soul) makes clear that she’s too pure and grand a woman to ever consider remarriage. This marks a new low in movie miracles. Faith here isn’t something private that might nurture us through this world’s cruel caprices; rather, it’s a promise that everything will work out, that a Superman-God will spin the world backwards for you.

Imagine a real child who has lost a parent in America’s desert wars. Imagine that child puffed up on Little Boy and its ilk, praying, hurting, maybe shouting arrgghh! Imagine that child taking to heart the lesson of this cynical, poisonous, stupid film: If the miracle fails to come, you must not have believed enough.