I have found, over years, that Christians have a remarkable capacity to live insular lives (do does everyone, really). I have asked people in churches where I serve to name people outside of the church with whom they have had thoughtful conversations. I have asked them to list the people they know for the Gospel. I usually get a short or a very short list.Read the rest.
So what? Why does it matter?
BTW - Mark has a really good book on church discipline that you can check out here.