Deissmann was professor of theology at the
Ruprecht Karl University of Heidelberg (1897–1908), and then at the
Friedrich Wilhelms University of Berlin (1908–1935). He was twice nominated for the Nobel Peace Prize, and held eight honorary doctorates from 6 different countries. In 1904 he founded, together with
Albrecht Dieterich, the
Eranos circle in Heidelberg. Members included
Ernst Troeltsch,
Max Weber,
Eberhard Gothein,
Georg Jellinek,
Karl Rathgen, and
Wilhelm Windelband. In Berlin, Deissmann's academic focus began to shift from Greek philology to the ecumenical movement, church reform and, significantly, international
Völkerverständigung (i.e. peace-promoting mutual understanding between nations and cultures). From 1914 until 1922 he produced a regular semi-political international communiqué, the
Evangelischer Wochenbrief (1914–1921), with its English equivalent
Protestant Weekly Letters (1914–1917). Its target audience was primarily influential German and American Christians, and it provided a forum for the advancement of peace and understanding among nations. In 1925 Deissmann became aware of the disintegration of ancient
Ephesus, a historically important archaeological site, partly excavated before World War I under the auspices of the Austrian Archaeological Institute. Deissmann campaigned single-handedly for several years, both on a national and international level, to raise awareness of the plight of Ephesus, and managed to organise funding for the archaeological work to recommence in 1926, and continued annually until 1929. Deissmann died on 5 April 1937, in Wünsdorf near Berlin, where he is buried in the local cemetery. ==Selected works by Deissmann==