After finishing high school in 1917 in Görlitz, Iwand studied Protestant theology at the University of Breslau (modern Wrocław, Poland).

Iwand's youngest daughter, the Veronika Geyer-Iwand (1943-1997), a popular religion teacher and the mayor of Beienrode, married pastor Klaus Geyer (1941-2003).

The son-in-law was convicted in 1998 of manslaughter in her brutal murder (July 25, 1997);[2] Geyer was the only German theologian ever to have been jailed after committing such a crime.

In November 1934 Iwand became professor of New Testament studies at the Herder Institute in Riga, Latvia.

Because of his participation in the Kirchenkampf struggle between the Nazi-backed so-called Deutsche Christen church and its oppositional Bekennende Kirche ("confessing church") he was forced out of his teaching position and from 1935 to 1937 headed illegal seminaries for training pastors in Blöstau, East Prussia (modern Vishniovka, Guryevsk, in the Kaliningrad enclave of Russia) and Jordan, Brandenburg (now in Poland).

[1] After World War II, Iwand was professor of systematic theology at the University of Göttingen,[1] where he worked closely with Ernst Wolf.

He was also at this time a council member of the Evangelical Church in Germany and the principal author of Darmstädter Wort zum politischen Weg unseres Volkes, a statement on relations between church and state after the end of Nazism and during the tensions of the Cold War.

In Beienrode he founded the Haus der helfenden Hände ("house of helping hands") to ease the plight of refugees from the former East Germany, later working for mutual understanding among Germans and the peoples of Eastern Europe.

In 1956 he was co-founder of the German social democratic publication Blätter für deutsche und internationale Politik, a monthly magazine covering German and international politics, and in 1958, together with Werner Schmauch (1905–1964) and Czech theologian Josef Hromádka (1889–1969), Iwand was a co-founder of the Christliche Friedenskonferenz (Christian Peace Conference) in Prague.