“I spent a year scratching,” Mr. Zuckerman writes. “I scratched and I scratched and I scratched.”

And he concluded that “religion wasn’t really so much a private, personal issue, but rather, a nonissue.” His interviewees just didn’t care about it.

Beyond reticence, Mr. Zuckerman found what he terms “benign indifference” and even “utter obliviousness.” The key word in his description of their benign indifference is “nice.” Religion, in their view, is “nice.” Jesus “was a nice man who taught some nice things.” The Bible “is full of nice stories and good morals, isn’t it?”

Beyond niceness came utter obliviousness.