Christianity is declining in the United States, according to new Pew surveys. And I have some news for my fellow Christians: This is actually bad news for Christianity.

That may seem obvious, but Russell Moore, an online acquaintance, a Baptist minister, and president of the Southern Baptist Ethics and Religious Liberty commission thinks there is a lot of upside to the rise of people who don't identify with a religion, otherwise known as the "nones." For him, they indicate the falling away of semi-Christians, and the declining cachet of Christianity as an empty social-marker. He writes:

Christianity isn't normal anymore, and that's good news. The Book of Acts, like the Gospels before it, shows us that the Christianity thrives when it is, as Kierkegaard put it, a sign of contradiction. Only a strange gospel can differentiate itself from the worlds we construct. But the strange, freakish, foolish old gospel is what God uses to save people and to resurrect churches (1 Cor. 1:20-22).

We do not have more atheists in America. We have more honest atheists in America. Again, that's good news. The gospel comes to sinners, not to the righteous. It is easier to speak a gospel to the lost than it is to speak a gospel to the kind-of-saved. [Moore to the Point]

Moore is right that as Christianity becomes less of a "default" religious affiliation, Christians have a greater opportunity to make a fresh appeal. But I think a case can be made for the fallen-away, for backsliders, the lukewarm, the non-practicing, the "cafeteria Catholics," and the "cultural Christians.”

Yes, some of the rise of the "nones" are the result of atheists and agnostics being more honest with themselves. But look at Barna Group's more sophisticated surveys of how people feel about church: 51 percent say it is "not too" or "not at all" important. Then look at statistics that drill down into church attendance: More than half of millennials and Gen Xers say they have not been to church in the last six months. These are troubling signs.

Fewer millennials going to church does mean fewer "cultural Christians." But does cleansing Christianity really outweigh the repercussions from letting the number of faithful dwindle?

When Billy Graham was preaching to Madison Square Garden, he wasn't addressing a coliseum of "nones" but people with a variety of church-y backgrounds. Many of them probably had a previous relationship not just with God, but with the hymn "Just As I Am," that played whenever he called them forward to make a decision for Christ. It was a revival, not a mass conversion.

Fewer "cultural Christians" also means a smaller population of Americans whose first instinct will be to defend their church from secularism in the cultural and political field. Like counterfeit bills, the presence of fake-Christians is a sign that the real thing is considered valuable. Cafeteria Catholics are proof that the Church is still serving something people feel the need to sample. The lack of semi-Christians might not be a moment of clarity, but a sign that our churches are boring, offering self-help pablum, rather than salvation.

At bottom, there may be some confessional reasons why Moore likes the more stark contrast between an honest "none" and a convinced Christian. Evangelical Protestantism converts people with bold proclamations, and invites them to a clear decision. For Catholics like me, divine grace catches sinners with G.K. Chesterton's fictive detective, "an unseen hook and an invisible line which is long enough to let him wander to the ends of the world and still to bring him back with a twitch upon the thread.”

The only good news in the reported plunge for Christians is that it alerts us to the sorry state of our churches. It's not just the rise of "honesty" among atheists, but a rise in the number of people who Christianity isn't reaching at all. It should be seen less as an opportunity for growth than a sign of decay and dissolution.