This article is based on a paper delivered at a Lutheran Missionary Conference in Bleckmar, Germany. The request was to give an overview of the development and the state of Reformed missiology with special reference to South Africa in order to stimulate the missiological debate in the German-Lutheran church. Within the space of an hour, one could only concentrate on the struggles and concerns of one’s own church and its missionary institute. The border lines of the article are laid down by the major themes of Reformed theology and missiology, such as ‘the Word alone’, ‘conversion’, ‘the formation of congregations’, ‘the glory of God’ and ‘ongoing reformation’. Readers are introduced to a few Reformed missiologists who had a decisive influence on the development of Reformed missiology, such as Gisbertus Voetius, Hendrik Kraemer, Arnoldus van Ruler, Johannes Verkuyl and Jürgen Moltmann. The initial Lutheran audience was informed about the self-caused problems in the Reformed tradition. Both the audience and the readership are cautioned not to withdraw from the basic Lutheran theologoumena, such as the ‘two-kingdom theory’. The next decade will be a decisive period for the missionary efforts of the churches. Ecumenical solidarity and cooperation will be needed to work out new strategies whereby churches will be enabled to continue with missionary work on a new financial basis.