We've had people say, "Now when I go to work, I don't feel uncomfortable talking to people of different races, and I go up and introduce myself, and I start making a new friend I wouldn't have done otherwise."

So one of the profound things we found when studying these congregations, the mixed ones, is just how much overlap and interracial ties that develop not only with the people in the congregation, but they start meeting each other's families, and their friends, and they go to each other's neighborhoods if they live in different neighborhoods, and at work they meet people they wouldn't otherwise met, and so it creates a whole new definition of what the group is.

Humor is so culturally based that when I try to tell a joke as me being a white American, if I tell other white Americans, they'll laugh. If I tell an African American, they might not laugh. In fact, they either might not find it funny, or they might find it offensive, and I didn't mean it to be offensive. So these are the sort of little things that build up over time, just like in a marriage. You know, the little things can build up over time.

If you move here from somewhere else, I often think if I move to Germany, for example, or if I move China and I go worship there I will understand and I'll be willing to give up a lot of my culture because I'm in somebody else's homeland. So I'm going to have to act German or Chinese, whatever that might mean.

I spent a lot of time developing in books why worshipping separately actually impacts inequality, economic, social, on and on. So I really do believe there are huge advantages to being together even though it's difficult, even though we have a lot to learn.

I really do think that every time you play a role well, you are in danger of being identified with that role until the next big thing comes along.

And then they would have the shoe removers on one side, and the non-shoe removers on the other side until they could work through coming to understand why we might both be trying to worship authentically, and because of our cultural background we have these different ideas. But it took a while.