Call-and-response style, yes, exactly. So whenever different groups get together then there has to be this long period of negotiation. How will we worship? What's acceptable? What's not? If I want to say "Amen" can I?

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.

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.

Scripture is vast, and people can pick and choose what they emphasize, and so for hundreds of years verses that said that you are to welcome the stranger, that with Christ there's neither Jew nor Greek, male nor female, we've broken down the dividing wall with the original church, where Christians were first called Christian was the church of Antioch in which for the first time you had Jews, Gentiles of all different ethnicities come together as one people. That's when they were called Christians.

I may have to shop with them. But on Sunday I don't want to have to worship with them. I want to be able to just be myself and let my hair down." It's also, of course, as we know, the seat of political organization and the affirming of your blackness and so on.

In part because they had no choice, right? If you were a slave, you did what the master said. And they said to worship: "You're going to worship with us."

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.