His post-war fame as a scholar rested on his effort to separate fiction from facts in his reconstruction of Jesus' life and in his subsequent treatment of the gospel of Matthew.
In 1934 he was appointed professor at the University of Königsberg, but in 1937 the Nazis withdrew his venia legendi and he had to stop lecturing.
[b] He suggested a tighter relationship between Jesus and the theology of the early church (in contrast to the 'First' and 'No Quest' periods ending in 1953).
Numbered among his opponents, Rudolf Bultmann argued for a divorce between the two, but their approaches remain similar in many aspects.
He affirmed: If the journey into this often misty country is to succeed, then the first requirement is the readiness for free and frank questioning, and the renunciation of an attitude which simply seeks the confirmation of its own judgements arising from a background of belief or of unbelief.