It's clearly the case that there's not some moment in American history when every evangelical is holding hands with every Catholic who is holding hands with every mainline Methodist, or what have you. Obviously, American Christianity was deeply divided in all kinds of ways at mid-century too. But there was a kind of convergence going on. Even though Reinhold Niebuhr, the great mainline Protestant theologian, didn't think highly of Billy Graham, he and Graham still, clearly, had more in common, both theologically and in their attitudes toward religion in public life.

I do think you can see, throughout American history, this temptation, and it's both a liberal and a conservative temptation, to take a healthy patriotism a little too far. For liberals the temptation is to say the purpose of politics is to straightforwardly bring the kingdom of God to Earth. For conservatives, I talk about Glenn Beck, the temptation is more apocalyptic and messianic, it's the temptation to say we did have a covenant with God, a literal covenant beginning with the Founding, and we are, like Israel in the Old Testament, falling away from it.

During a frustrating argument with a Roman Catholic cardinal, Napoleon Bonaparte supposedly burst out: “Your eminence, are you not aware that I have the power to destroy the Catholic Church?” The cardinal, the anecdote goes, responded ruefully: “Your majesty, we, the Catholic clergy, have done our best to destroy the church for the last 1,800 years. We have not succeeded, and neither will you.”

The decline of institutional Christianity over the last 40 or 50 years has empowered a side of American religion that has always been there. The sort of do-it-yourself, "create your own Jesus" kind of faith. But, the forms that faith takes do have a real reason they are so appealing.

Even secular people can't really escape from the need to rest their ideas on some belief, some sort of commitment that is not scientific commitment.

The fact that institutional churches have gone into decline doesn't mean that we're going to enter some purely secular age. Secular people need to be aware of that.

Our culture has few taboos that can't be violated, and our establishment has largely given up on setting standards in the first place. Except where Islam is concerned. There, the standards are established under threat of violence, and accepted out of a mix of self-preservation and self-loathing. This is what decadence looks like: a frantic coarseness that "bravely" trashes its own values and traditions, and then knuckles under swiftly to totalitarianism and brute force.