When he climbs into his pulpit on Sundays, Bowen shouts ‘God is good!’ and the people shout back, in unison, ‘All the time!’

Will Bowen takes “uncomplaining” to an extreme. Bowen doesn’t gripe about anything, ever. A reporter asks, “How are you doing?” “Great!” he answers. “Can’t complain.” Really? You can’t complain? What do you do when your car breaks down? “I call the mechanic and ask him to fix my car.” How about when something terrible and unfair happens for no reason? Everything happens for a reason, Bowen responds. “Absolutely. In my theology, that’s what I believe.” When he climbs into the pulpit of his church in Kansas City, Mo., each Sunday, he shouts, “God is good!” and the congregation shouts back, “All the time!”

Complaining has become such an automatic response to life’s little setbacks that people don’t even realize they’re doing it, Bowen says. Eighteen months ago, he was preaching a sermon on prosperity and was inspired to give a purple rubber bracelet to each person in his 280-member congregation. The bracelet, which says SPIRIT, was to remind people of the hazards of complaining. Negative talk produces negative thoughts; negative thoughts produce negative results, says Bowen. To live a happy and prosperous life, you have to stop complaining. To his flock, he submitted this challenge: stop complaining for 21 days. Put on the bracelet, and each time you hear yourself complain, switch the bracelet to the other wrist and start the clock over. It took Bowen three months to stop complaining; other churchgoers took much longer. Since that summer sermon, God has been very, very good to Will Bowen. Local news organizations picked up his story and Bowen wrote a book, now in its seventh printing. He went on the “Today” show and then on “Oprah.” His church has mailed 5 million purple SPIRIT bracelets all over the world and continues to do so at a rate of 25,000 to 50,000 per week.

Positive thinking is hardly new among American Christians — Norman Vincent Peale was a Protestant minister — but it’s finding a newly receptive audience. Last month Kerry and Chris Shook, a husband-and-wife team who run The Woodlands, a megachurch near Houston, published their book “One Month to Live.” The book doesn’t advocate a complaint-free existence, exactly, but it offers a program to help people treasure each day. “If you live the next 30 days as if they were your last, you won’t be wasting time, you won’t be complaining, you won’t be thinking, ‘If only I had this, if only I had that’,” says Kerry. “One Month to Live” climbed to No. 3 on the New York Times’s self-help best-seller list, where it has stayed for the past two weeks.

To those for whom complaining itself is a kind of religion, and who believe that efforts to sweep away negative thoughts with bracelets and 30-day programs are shallow and irritating, consider this: psychologists recommend similar tricks to their patients who need a walk on the bright side. “In cognitive behavioral therapy, there’s a technique called ‘thought stopping’,” in which a therapist helps a patient replace a negative thought with a positive one, says Susan Vaughan, a psychiatrist at Columbia University. Even in a case of an injustice, “I would have you not complain because it won’t actually help your mental health, it will make you feel worse, and people will react negatively to you.”

Dr. Laura Schlessinger would disagree. In her new book, “Stop Whining, Start Living,” Dr. Laura insists that a few things are worth complaining about: in those cases, complain, make it short and move on. Life is “crappy and unfair,” but it’s also full of blessings.