At the same time, DeWitt is something of a reality check for many atheists, whose principles rarely cost them more than the price of “The God Delusion” in paperback. DeWitt refuses to leave DeRidder, a place where religion, politics and family pride are indivisible. Six months after he was “outed” as an atheist he lost his job and his wife — both, he says, as a direct consequence. Only a handful of his 100-plus relatives from DeRidder still speak to him. When I visited him, in late June, his house was in foreclosure, and he was contemplating moving into his 2007 Chrysler PT Cruiser. This is the kind of environment where godlessness remains a real struggle and raises questions that could ramify across the rest of the country. Is the “new atheism” part of a much broader secularizing trend, like the one that started emptying out the churches in European towns and villages a century ago? Or is it just a ticket out of town?

DeRidder is a four-hour drive northwest of New Orleans, near the Texas border. It is a tiny place, surrounded by thick forests of long-leaf pine, where many of the 10,000-odd residents have known one another all their lives. There is one major commercial strip lined with fast-food restaurants and chain stores, and in the rest of town it is difficult to drive a block without passing a church. Many of them are Pentecostals, part of the revivalist Christian movement in which worshipers often speak in tongues — babbling in what is thought to be a sacred language — sometimes while writhing on the floor. In the local Walmart, it’s easy to recognize the more conservative Pentecostal women, who wear modest, long dresses in a high-waisted style, their hair, which they do not cut, pulled neatly into buns.

When I first met Jerry DeWitt, I half expected a provincial contrarian hungry for attention. Instead, he was mild and apologetic, a short, baby-faced man with a gentle smile and a neatly trimmed dark beard. He was earnest and warm, and I soon discovered that many of his fellow townspeople cannot help liking him, no matter how much they dislike his atheism. He appears to have reached his conclusions about God with reluctance, and with remorse for the pain he has caused his friends and family. He seems to bear no grudge toward them. “At every atheist event I go to, there’s always someone who’s been hurt by religion, who wants me to tell him all preachers are charlatans,” DeWitt told me, soon after we met. “I always have to disappoint them. The ones I know are mostly very good people.”

DeWitt is a native son in every way, and this must make his apostasy all the more difficult for others to make sense of and to accept. He is descended from a long line of preachers on both sides of the family. His paternal grandfather helped establish at least 16 different churches­ in Louisiana, including one in DeRidder, he told me. (I found 69 churches in the town directory, though some may be inactive.) DeWitt grew up in the church, but it was only at 17, after being “saved” during a weekend visit to Jimmy Swaggart’s church in Baton Rouge, that he became a passionate Christian. Weeks later he spoke in tongues for the first time. Soon after that, sitting in church, he heard his pastor call on him to deliver a homily. Terrified, he asked if he could have a few minutes to pray for guidance. He stepped to the pulpit with his finger on a passage from the Gospel of Mark, and spoke for 15 minutes on the “seed of David.” The crowd loved it. “It was the biggest high I’d ever had,” he told me. “I knew right then that preaching was what I wanted to do with the rest of my life.” He married a local girl at age 20, and two weeks after the wedding, he received an invitation to speak at a camp meeting in Lucedale, Miss. There he preached to overflow crowds of whooping Pentecostals who were speaking in tongues.

He and his wife began touring the South, building a reputation for the power of his sermons. It was a tremendous ego charge, especially for a short, chubby young man with dyslexia. For the first time, he was treated with respect, even awe. “I had this whole prophet persona going on. I wouldn’t really mix with people before the sermon,” he told me. “All kinds of people were seeing miracles, and I believed it 100 percent.”

For the next few years, DeWitt preached across the South, doing itinerant jobs to pay the bills. In 2004 he became a full-time preacher at a church near DeRidder. By that time, though, he had drifted away from the literal claims of Pentecostal doctrine and espoused a more liberal Christianity. He had begun reading more widely (he never got a college degree), starting with Carl Sagan’s books on science and moving on to Joseph Campbell and others. But equally, he told me, he found it unbearable to promote beliefs that only seemed to sow confusion and self-blame. He recalled how one middle-aged woman in his church who was suffering from heart disease asked him anxiously: “How am I going to believe for salvation when I can’t believe enough to heal?”

Finally he began to feel that his rationalist impulses were alienating and hurting his flock, and he resigned — reluctantly, he said, because he loved the human side of being a pastor, “playing Mr. Fix-It for the community.” He continued preaching part time for a while, invoking an ever more misty and ethereal God. By now he had also read Dawkins and Hitchens, and even weak-tea Christianity was becoming hard to swallow. He preached his last sermon in April 2011, in the town of Cut and Shoot, Tex. A month later, Natosha Davis called, and DeWitt found himself unable to pray at all.