At the Law and Liberty site, I review Stephen Bullivant’s fine new book on the rise of the Nones and argue that the middle is falling out of American religion in favor of the extremes on either end. Here’s an excerpt:

Bullivant rejects the conventional view that nonverts tend to come from the ranks of people whose religious affiliation was indifferent to begin with—those who were Christians in name only. Many Nones “were once genuinely believing and practicing—even ‘painfully devout,’” he writes. It isn’t simply weak Christians who are drifting away, but true believers. As a consequence, he believes, the crisis facing American Christianity is real and worse than many would like to admit.

As evidence, Bullivant points to data that shows that more and more Americans who regularly attended church as children become Nones as adults. “These were church kids,” he notes. But attending church regularly as a kid isn’t really a proxy for religious commitment; lots of kids go because their parents make them. And some data refutes Bullivant’s argument. For decades, the GSS has asked respondents to rate the strength of their religious affiliation. The percentage of respondents who say their religious affiliation is “strong” has gone down a bit since 1990, but not by much: from 37 percent to 34 percent.

By contrast, the percentage of respondents who rate their religious affiliation as only “somewhat strong” has gone down dramatically, from 14 percent to 4 percent. As in so many areas of American life, the middle seems to be dropping out in favor of the extremes on either end. If current trends continue, American religion will be polarized between very committed believers and people who reject organized religion entirely. That’s not a recipe for a harmonious society.

Of course, even if it’s only nominal Christians who are leaving, that itself reflects something important about the religion’s waning influence in American life, as Bullivant insightfully observes. Nominal adherence tells you how a brand is doing, which is why “successful sports teams often have vast numbers of casual fans.” It’s fun to root for a winning team. When a team falls on hard times, its fair-weather fans desert it. More than anything else, it seems, that describes what’s happening to American Christianity right now.

You can read the full review here.