He then took a position teaching New Testament at Heidelberg and was called, in 1954, to the University of Zurich, where he was made full professor in 1956.
One of Conzelmann's major works was Die Mitte der Zeit (Tübingen 1954), literally 'The Middle of Time', which was translated into English under the title, The Theology of St. Luke.
Conzelmann, along with other post-Bultmannian scholars, challenged the view that Jesus was an apocalyptic figure, but rather focused on the message of Christ as the kingdom of God breaking into the present.
Perhaps Conzelmann's main contribution to the study of Luke's Gospel was his contention that Luke changed the emphasis in Jesus' teaching from an expectation that he (Jesus) would return shortly after his death, resurrection and ascension (a belief in the imminent parousia) to seeing God at work in history and therefore that the early Christians needed to find ways of living as disciples of Christ 'in the long haul' through history.
These details have been challenged by later scholars - for example by asking where John the Baptist most accurately fits and if the life of Jesus really was a 'Satan free zone'.