One person reported without irony that if you slow down the sound of a cricket you can hear it sing Handel’s “Hallelujah” chorus. Illustration by Paul Rodgers

The United States, as we know, is a very religious country, but the figures still have the power to amaze. Since 1996, according to Gallup polls, between thirty-five and forty-seven per cent of Americans have described themselves as “evangelical” or “born again”; two-thirds mostly or wholly believe that angels and devils are at work in the world. Given these figures, skeptics would do well to find out what is going on in evangelical churches, and that is what T. M. Luhrmann tries to explain in her new book, “When God Talks Back: Understanding the American Evangelical Relationship with God” (Knopf). Luhrmann is a well-qualified guide: an anthropologist specializing in esoteric faiths. Her dissertation was on witch-and-warlock cults in contemporary England. Later, she wrote a book on the Parsis, a Zoroastrian community in India. Her most recent book was the highly praised “Of Two Minds,” a study of psychiatric residents and their handling of patients who had visions, among other problems. Almost always, Luhrmann has written with sympathy, not scorn, for these convinced people.

Nevertheless, she is a scientist, and believes in evidence. She spent two years as a full-time member of an evangelical church in Chicago, and another two years in a congregation in Palo Alto. (Those are the cities where she was teaching during that period, first at the University of Chicago, then at Stanford.) Both churches were part of the Vineyard Christian Fellowship, which came together in California in the nineteen-sixties and seventies, and now has about fifteen hundred congregations around the world. Most of the members of the churches that Luhrmann attended were white, middle class, college-educated, and centrist. They weren’t Pentecostals (that is, most of them didn’t speak in tongues or heal the sick). But neither were they just conservative Christians. In Luhrmann’s words, they placed “a flamboyant emphasis on the direct experience of God.” If you made contact with him, they believed, he would become your intimate, someone “who loves and cuddles you.”

How do you find this God? First, you train yourself to recognize the evidence of his operation in your life. One Vineyard parishioner, Augusta, described feeling “goosebumps and just warm all over and just very peaceful, and I know that he’s there.” Or if a thought pops into your head that’s not the kind of thought you normally have, and, above all, if it strangely matches something else in your recent experience, that is likely to be God speaking. Sarah, a member of the Palo Alto congregation, told Luhrmann that one morning, when she had finished her prayers, she went on sitting in her prayer chair and let her mind wander. She kept seeing a picture with boats in it. Then the phone rang. It was the pastor. She asked him why he was calling. “And he said, ‘I don’t know. I just felt like I was supposed to call you.’ And it clicked then, that the picture I had seen wasn’t a distraction from my prayers but was connected to my prayers, I told him about this picture that I’d gotten. And he told me . . . that several people had gotten the same picture, and that it was about Jesus with his hands on the wheel of a ship.”

In the second step, worshippers, when they recognize that God is with them, must learn to treat him like an intimate. This injunction, probably more than anything else in Luhrmann’s book, will puzzle readers who were raised in other religious traditions. The Vineyarders have no interest in God as a figure of majesty, or of judgment. They wear shorts and sneakers to church on Sunday. In Chicago, the service begins with “free time,” during which you needn’t sit down. You can dance or sway in the aisles, Luhrmann says, or have doughnuts and coffee from the snack table. Once you do sit down (you can bring your coffee with you), you hear a sermon augmented by a PowerPoint presentation.

This casualness carries over to conversations with God. The Vineyarders asked him “for admission to specific colleges, for the healing of specific illness—even, it is true, for specific red convertible cars.” Some Vineyard women had a regular “date night” with Jesus. They would serve a special dinner, set a place for him at the table, chat with him. He guided the Vineyarders every minute of the day. Sarah told Luhrmann how, one day, after a lunch at a restaurant with fellow-parishioners, she was feeling good about herself, whereupon, as she was crossing the parking lot, a bird shat on her blouse. God, she explained to Luhrmann, was giving her a little slap on the wrist for her self-satisfaction. Sarah accepted the chastisement, but others don’t. They may get furious with God. And, according to some evangelicals, he feels bad when this happens. In “Disappointment with God” (1988), the religious writer Philip Yancey claims that God can’t bear for us to turn away from him. He longs for us to like him. It is hard to understand how evangelicals, most of whom are regular Bible readers, could come to this conclusion about the God of Abraham and Job.

So the third step is to “develop your heart”—that is, to cultivate the emotions that are appropriate to receiving God’s unconditional love. There are exercises for this, notably, what Luhrmann calls “crying in the presence of God.” During sermons, the congregation wept—sometimes the pastor wept, too. In the small weekly meetings called “house group,” people cried their eyes out. “At one conference I attended,” Luhrmann writes, “four men spoke, one after the other, and every last one of them wept by the time he was done.” Above all, the congregants cried when they were “prayed over” by their fellows. At the end of the service, if they had troubles, they went over to the “prayer team” standing against a side wall, and the team huddled around them, touched them, and prayed over them, “asking God to make them feel safe, loved, and protected—wrapped in his arms, soothed by his embrace, washed by his forgiveness.” If, under such ministrations, you didn’t cry, this was something you had to explain.

The one important fault of “When God Talks Back,” and yet the thing that makes it intriguing—makes it more than an ethnography—is its wavering attitude toward its subject. From chapter to chapter, you can’t quite figure out how Luhrmann feels about the Vineyarders’ spiritual project. Occasionally, she allows herself sarcastic remarks—for some of the congregants, she says, the product of prayer is a state of “feel-good blurries”—and she describes some scenes with unmistakably comic intent. At one point, she and another church member, Elaine, go to a Vineyard-sponsored conference called “The Art of Hearing God.” Luhrmann writes, “The leader explained to us that scientists had discovered that if you slow down the sounds a cricket makes, you will find that the cricket is actually singing the ‘Hallelujah’ chorus to Handel’s Messiah. Elaine thought that this was really neat and repeated it to our house group without a trace of irony.” Luhrmann says that Elaine was “almost wantonly uninterested in probabilistic logic.”

Another odd thing about the Vineyarders, at least as described by Luhrmann, is that they seem to perform no social service. Unlike other serious evangelical groups, which are making headway as missionaries in Africa, there appears to be very little spreading of the faith, or even just of well-being—schools, hostels, soup kitchens—on the part of the congregations Luhrmann joined. Maybe she left out their charitable projects on the ground that her book, as its title tells us, is about the Vineyarders’ relationship with God. But I don’t think so, because now and then she comments dryly on their self-concern. Her fellow-congregant Hannah, she says, got mad at God, “not because he allowed genocide in Darfur, but because little things happened in her life that she did not like: ‘I was upset with him for making me a dorm counselor.’ ” Vineyarders may implore God to help fellow-members of their church, but otherwise, in Luhrmann’s account, pretty much everything seems to be about themselves.