From the latest issue of Logia, a fine article, (which is online) by Prof. Detlev Schulz, on the mission theology. It is entitled In Search of the Proprium of Lutheran Mission: Eight Theses.
Here is a taste:
Thesis One: The subject of Lutheran mission is the Triune God, the Father, Son, and Holy Spirit, who creates, redeems, and sanctifes. For his saving mission to the world, the Triune God calls the church into his service as his instrument. He alone provides and grants success and victory to her mission. Thus, confidence and unwavering trust should be placed in this God and not in our own human abilities and insights.
Thesis Three: Lutheran mission considers the means of grace, that is, the gospel in word and sacrament, not only as her visible and reliable marks (notae ecclesiae) by which the church of Jesus Christ, despite her hidden nature, can be seen and identified, but also as the definitive and exclusive content of her task.
From this follows Lutheran mission’s focus on the proclamation of the word and the administration of the sacraments. From this it follows that all other services in mission to the healthy and the sick are actually aligned and subordinated to the service of the gospel.
Finally, from this it follows that the struggle for the purity of word and sacrament is also a constant obligation for Lutheran mission.