In this contribution "On the Doctrine of God," the focus is on the two central concepts of the Trinity and the Kingdom of God. In contrast to humanistic and monotheistic interpretations, Moltmann develops a trinitarian hermeneutics of biblically generated history. By "trinitarian thinking," he means the overcoming of subjective particular thinking and the unfolding of thinking in relationships, communities, and environments. This leads to the presentation of a consciously social doctrine of the Trinity and a new turn towards freedom. This is the first volume of new contributions to theology, in which Jürgen Moltmann reworks the most important concepts and teachings of theology.