I found this quote from an article on the PCA and emerging church movement.
"You can’t have a hit-and-run approach to ministry. You have to love a place to minister to a place. The people need to become your people. We push for a geographical integration of church, neighborhood, and work. The closer these things are, the more natural it is to live a seamless life. The more distance there is, the more you need artificial props—programs—to create community. Relationships need leisure to develop. That’s why we talk about a long-term commitment to a particular place (2-3 mile circle)."