Born in 1943 in Germany. He studied German studies and theology in Bonn, specializing in New Testament (1972). Professor of New Testament at Copenhagen (1978-1980) and since 1980 at the University of Heidelberg. It belongs to the Evangelical Church.

Among his works translated into Castilian we can include: Sociology of the Jesus movement, 1979; Sociology studies of early Christianity, 1985; The open door, 1993; local color and historical context in the Gospels, 1997; The historical, 1999 Jesus; and Religion of the early Christians, 2002.