There's one denomination in particular, though, that has pushed very hard to be multiracial in its denomination - not only its denomination but, I mean, in its congregations, and it's called the Evangelical Covenant Church, http://www.covchurch.org/ which is headquartered in Chicago. Their whole goal is that's the kind of churches they start, multiracial, and I think they say now 20 percent of their churches are that.

One of the things we find when we talk to people that attend these congregations, they all have social cost to it. People want to know why they're doing that. Sometimes they're questions about selling out on their race or "Are we not good enough that you have to go to this kind of congregation and not ours?" So there are costs to it, and I think they're a little bit higher in the South because of its history.

Then of course there are bigger things that matter, like who do I see up there in the congregation? Do I see myself up there? Well, I don't.

So different groups have different definitions, and then they clash on those. So it takes adept leadership to say we're going to work through these.

But in the US, when you have two separate cultures, each with its right, each of which has come to exist in this political entity in the last couple hundred years, each feeling like, "I have the right to hold onto my culture," and that's what makes it difficult.

I think it's going to open up a wider place for a discussion about we ought to come together in our churches, in our neighborhoods, in our work places, in our clubs and our networks. I think it'll be more acceptable to talk about it. We'll see what happens. It'll take some time. But I think it will.

We studied a mosque, and this is when we were at Notre Dame, and in this mosque they had people from a variety of countries, most of them immigrants. In some of the countries, when you go into a mosque you remove your shoes. To not do so could be punishable even by death in that nation. In other countries, it would be a great offense to remove their shoes when they come into the mosque, a sign of disrespect.