I have been reading Guder's marvellous little book, The Incarnation and the Church's Witness.  A must read.  Shame on me for not reading it before.  Here are some insights.

This focus upon the incarnation of Jesus Christ, the Word become flesh, as a way of talking about and understanding mission addresses at least two major and interrelated concerns in the contemporary debate about mission. It responds, first, to the widespread critique of the modern missionary movement which addresses the way that mission has often been done. Many of the missionary methods and strategies have contradicted both the teaching and actions of Jesus as he trained his disciples to continue his ministry. The message may have been the gospel, but the way the message was made known was often not congruent with the gospel. The attempt to interpret mission in terms of the incarnation of Jesus suggests that the earlier European mission strategies should be replaced by a theology and praxis of mission rooted in and defined by the life and ministry of Jesus.

Second, by focusing on the incarnation as testified to in Scripture, this approach suggests a Biblical basis of a mission that addresses its motivation, its content, and its method in direct relationship to the life and ministry of Jesus. The why, what, and how of Christian witness of being explored exegetical in ways that most pioneers of Western mission would not have considered. ...   we find ourselves now able to cut through the centuries of European interpretation and cultural adaptation of the Gospels. We know more about how the early church functioned, and that knowledge is helping us rediscover the character of early Christian mission. Much of what results from the study can be drawn together in the concept of incarnational mission”.

By incarnational mission I mean the understanding and practice of Christian witness that is rooted in and shaped by the life, Ministry, suffering death, and resurrection of Jesus.

Darrel Guder,   The Incarnation  and the Church’s Witness,  (Eugene: Wipf and Stock, 1999)  page xii