Regnum Studies in Mission are born from the lived experience of Christians and Christian communities in mission, especially but not solely in the fast growing churches among the poor of the world. These churches have more to tell than stories of growth. They are making significant impacts on their cultures in the cause of Christ. They are producing ‘cultural products’ which express the reality of Christian faith, hope and love in their societies. Regnum Studies in Mission are the fruit often of rigorous research to the highest international standards and always of authentic Christian engagement in the transformation of people and societies. And these are for the world. The formation of Christian theology, missiology and practice in the twenty-first century will depend to a great extent on the active participation of growing churches contributing biblical and culturally appropriate expressions of Christian practice to inform World Christianity.