Theissen inquires into the correlation between the theological and ethical convictions of the first Christians as well as the social realities of the world in which they lived. He expands the form-critical inquiry into the Sitz im Leben of early Christian texts to ask about the significance of early Christian convictions in society.
Gerd Theißen (or Theissen; born 24 April 1943) is a German Protestant theologian and New Testament scholar. He is Professor of New Testament Theology at the University of Heidelberg.