I posted a great excerpt from Volf's book Free of Charge yesterday on the Peacemaker blog, Route 5:9.
Today it's from his more academic book, Exclusion and Embrace.
As the Gospel has been preached to many nations, the church has taken root in many cultures, changing them as well as being profoundly shaped by them. Yet the many churches in diverse cultures are one, just as the triune God is one. No church in a given culture may isolate itself from other churches in other cultures declaring itself sufficient to itself and to its own culture. Every church must be open to all other churches. We often think of a local church as a part of the universal church. We would do well also to invert this claim. Every local church is a catholic community because, in a profound sense, all other churches are a part of that church, all of them shape its identity. As all churches together form a world-wide ecumenical community, so each church in a given culture is a catholic community. Each church must therefore say, "I am not only I; all other churches, rooted in diverse cultures, belong to me too." Each needs all to be properly itself. (page 51)