Every Christian in every time and place is going to be tempted by certain forms of heresy. I'm sure I'm tempted by my own.

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.

One of the things I try to do is take seriously some of the forms of American religion that people consider to be shallow and try and figure out why they have such a strong appeal and tease out the theology they actually represent.

Americans are an "almost chosen people," which is meant to suggest that there are clear parallels, literal, theological and everything else, between the American story and the Old Testament story of Israel and then the broader story of the Christian church. It's OK to recognize the parallels. It's OK to invoke them. But, you have to keep that "almost" in front of the "chosen." You can't go all the way and say, "America is Israel, America is the Church." That's where I think patriotism shades into, what I call, the heresy of nationalism.

I think that secular liberals need to recognize that they are still, often, hanging their worldview on what are metaphysical ideas.

In the end, you do need institutions to transmit the faith for the long haul. That's why I make the case that, in certain ways, American Protestants could stand to recover the denominationalism that they've left behind over the last 50 years. They are real values in having a confessional tradition that can sustain your faith over the long term.

No one doubts that pure libertarianism is simple, but that's just why it remains on the ideological fringe - because it boils down the most difficult questions in human affairs to a simple equation, a What Would the Market Do bumper sticker.