In the new movie “Fireproof,” Caleb is a fire captain and Katherine is PR director for a hospital. Their marriage is crashing after seven years. Whose fault is it? Probably more his than hers, but it’s not clear. He has an anger problem and a pornography problem. She’s aloof, too perfect, and has a wandering eye at work.

But when Kat asks for a divorce, it’s Caleb who digs in to fight for their marriage, with encouragement from his dad, a new Christian. “The Love Dare,” a 40-day rescue plan, is what slowly turns him, and the relationship, around.

Through plot twists we learn that the rescue plan has been found to work as well for a woman on the brink as for a man, and for couples a generation older than the young Holts. Caleb’s lieutenant, a black guy named Michael, turns out to have it together a lot better both spiritually and maritally than his boss.

While the movie makes a direct but non-pushy evangelistic appeal, this isn’t church or a revival meeting — it’s terrific entertainment. What could be a heavy couple of hours is deftly lightened by Kat and Caleb’s funny coworkers at the hospital and the firehouse, as well as by the deadpan neighbor who is always outdoors at the wrong time.

“Fireproof” was shot on a shoestring budget and with few professional actors. It’s the third feature film from Sherwood Baptist Church in Albany, Georgia, which previously shook up the cinema world with “Facing the Giants.” At their website, FireproofMyMarriage.com, the “Love Dare” book is also for sale.

Donna and I loved this movie because, like most couples, we’ve had to learn a lot of lessons about marriage the hard way. We’re encouraging all our friends to see it and talk it up. Its theater run won’t be very wide or long, given the bias of Hollywood and big distributors toward a totally different ethic and message. Catch it while you can, or if necessary, get the DVD later on. This one’s worth owning and seeing again!