I'm watching a new 36-lecture series called "The American Mind," taught by Professor Allen C. Guelzo, that raises the importance of religion in American thinking to, for me, a new level. Right up there with the Enlightenment, Locke, Hobbes, Hume, etc. We still haven't reached the Civil War in the course, but still.
At this time, the period covering the first decades of the 1800s, revivals and awakenings were as common as chicken soup. And often as transitory. Easy in as the passions dictate under the tent, easy out as boredom sets in. Or, if you are serious, you retreat from normal society completely, thereby not altering it. Not important either way.
But philosophers - the "moral" philosophers mostly relying on thinkers out of Scotland rather than Jonathan Edwards-type theologians and well before the pragmatists - figured that what religion might not prove, common sense could. To make a (very) long story short, what you see is what is real, and thus your moral judgments are just as real. (After all, they are based on what you see!)
Unfortunately, the moral philosophy didn't hold up. Not only logically, but the different Protestant denominations couldn't get together because of all the different stuff they had to swallow, and it all fell apart. But Puritan Calvinism, the hunger for revivals, didn't go away. It still hasn't. It lingers under that nearby steeple. The question is: George W. Bush aside, what that means for the rest of us.