A constructive revision of trinitarian missio Dei theology, John Flett's Witness of God argues in conversation with Karl Barth and host of other historical theologians, that the neglect of mission as a theological locus has harmful consequences for understanding both the nature of God's connection with the world and the corresponding nature of the Christian community.
Flett maintains that mission/witness is an integral part of God's being, not a secondary characteristic, and contends that the church - if we truly seek to reflect the fullness of God's being - must reflect this truth by becoming a missionary community.