We've done a lot of studies to see when they do happen, why, and I mean there's a variety of reasons. But one, it starts with a commitment where they decide this is going to be who we are. Maybe it's out of their faith, a new way of looking at their faith, that we must be integrated across race.

And different traditions stress different - so then there's that. I talked to an African American who says before she goes into an interracial church, she sits in her car and she listens to gospel music to get her fill, and she goes into an interracial church where they don't do gospel music, and she's ready to accept the other sorts of ways of worshipping. So there's that.

I mean, so if I've talked to whites in City of Refuge, sometimes they'll wonder, "Why do we do things a certain way, and why do we make a big deal out of events?" And what's happening is they're falling back on their understanding of the way that church should work. It's not always working exactly like that, and they feel frustration or confusion. Sometimes people leave. That's certainly common in mixed churches.

What sort of difficulties would happen when people of different cultures try to come together to worship? Tiny little things such as let's tell jokes with each other.

So you find a lot of these sixth Americans congregate in these interracial congregations. They hang out together at work, at school, wherever.

Now they had to sit in separate places and sometimes they'd even have to sit outside and look through the windows. But they did worship together.

So they actually put it into their mission statement, and they start changing things as a result. They may change how worship works. They may actively recruit folks and try and get them to come and help them to feel comfortable and get them involved in leadership, and there's a variety of ways.