(RNS) Losing his religion cost Bart Campolo a career as an evangelical ministry leader and threatened to alienate many of those he held dear — especially his beloved father, the well-known evangelical educator Tony Campolo.

Why would anyone choose that?

Well, it turns out, he didn’t.

“I didn’t choose not to believe in God,” Bart Campolo writes in his new book, “Why I Left, Why I Stayed,” co-authored with his father. Campolo, now humanist chaplain at the University of Southern California, adds: “Like so many other post-Christians, I didn’t manufacture my own de-conversion on purpose; it happened to me.”

The Campolos’ book is hardly the first conversation on the degree to which we control our beliefs. But coming at a time of growing religious disaffiliation, it casts helpful new light on why belief dies (or is never born) and, perhaps more important, what happens afterward.

Given the demonstrated benefits of religious participation, both for individuals and the larger society, wouldn’t it be better if all the ex- and not-yet believers went to church?

New York Times columnist Ross Douthat thinks so.

In a piece published on Easter weekend, Douthat, a conservative Catholic, urged the nonreligious to start or resume going to church. Accurately describing the political and cultural compatibility between progressive churches and the liberals who swell the ranks of the nonreligious demographic, Douthat suggests that church participation would not require much of a leap for these theoretical new attendees.

“I understand that there’s the minor problem of actual belief,” Douthat writes. “But many of you do believe in the kind of open Gospel that a lot of mainline churches preach.”

But for many, this “minor” problem of belief is actually quite major, especially when it comes to supernatural phenomena that are such a focus of worship. And Christianity, as a religion that hinges on core beliefs (more than actions) to a degree unseen with other major religions around the world, is uniquely vulnerable to this problem.

Whatever the hurdles, Tony Campolo argues someone who wants to believe can believe.

It’s a matter of making a choice, he contends, and then immersing oneself in “plausibility structures” that reinforce that choice and fend off doubt.

Such structures are, of course, the tried-and-true practices of contemporary Christianity: daily habits such as prayer, study groups, retreats, close social ties with fellow believers, and the like. Evidence — the existence of millions upon millions of sincerely believing Christians in this country — suggests that these belief-nurturing strategies work.

But not for everyone. And the number of those who cannot, or will not, make the leap continues to grow.

Increasingly, believers’ and prospective believers’ walks through life expose them to more secular people and social dynamics. As these pesky reminders of nonbelief become more frequent and conspicuous, the social penalty paid for being an “out” nonbeliever weakens.

All this points to another problem with plausibility structures: Why would nonbelievers feel compelled to strive for and nurture belief in something their thoughts and experiences tell them is not true?

As religion writer Jonathan Malesic pointed out in response to Douthat, “The biggest reason people have left the mainline is not sociological. It’s theological. People simply don’t believe what the churches teach about God. No social or material inducement may make a difference.”

Blame it on the secular zeitgeist, and the advance of a scientific mindset that makes people more suspicious of supernatural claims. Whatever the cause, belief is harder to muster than it used to be in the Western world, and for lots of people, no amount of wishful thinking will help.

Considering the testimonials of believers and nonbelievers, one begins to see that this is a debate with no clear resolution. It’s as likely to yield a final answer as that better-known conundrum about what comes first, the chicken or the egg.

What is clear is the imperative for people to navigate their clashing convictions with care and compassion, something the Campolos have done inspiringly well.

In the conclusion to their book, the father and son describe how, rather than denouncing one another and ending their relationship, they found a way to accept each other and celebrate all they continue to have in common, even after Bart’s de-conversion:

“While we come to it differently,” the Campolos write, “each of us always reaches the same conclusion about this life: Love is the most excellent way. Moreover, each of us is both sure and content that the other has found that way. For now, at least, that is enough.”

It certainly is. And if each debate about the existence of God and nature of faith could end on this gracious note, we’d all be better for it.

(Tom Krattenmaker is a writer specializing in religion in public life. His latest book is “Confessions of a Secular Jesus Follower”)