Stanley Hauerwas has recently published his most sophisticated treatment of mission and evangelism.
Stanley Hauerwas, "Beyond the Boundaries: The Church as Mission" in Walk Humbly with the Lord: Church and Mission Engaging Plurality (ed. Viggo Mortensen and Andreas Østerlund Nielsen; Grand Rapids: Eerdmans, 2010), 53-69.
Read it at Google Books.
Hauerwas is one of my main advisors in my doctoral work here at Duke and I approach the topic similar to the way he does here. He draws heavily on John Howard Yoder, responds to Nathan Kerr, and cites Karl Barth, Lesslie Newbigin, and Bryan Stone approvingly.
(Note also the reference to former Duke students Derek Woodard-Lehmann (now at Princeton) and Dan Barber).
This is not easy reading. It is part of a broader conversation in theology, political theology, and ethics.