German Lutheran theologian, pastor, and member of the anti-Nazi resistance, executed by the SS at Flossenbürg on 9 April 1945, two weeks before the camp's liberation. Bonhoeffer was 39. His life and his writings are now effectively inseparable: every sentence in the theological corpus reads differently knowing what he did with the last twelve years of his life and how they ended.
His theological formation was brilliant and rapid. A Berlin dissertation at 21, habilitation at 24, a teaching post at the University of Berlin, a year at Union Theological Seminary in New York (where the Black church in Harlem marked him deeply), active involvement in the Confessing Church from 1933 against the Nazi co-option of the German Protestant establishment, and leadership of an illegal seminary at Finkenwalde from 1935 to 1937. The Cost of Discipleship (1937), written out of that seminary, is his best-known prewar work — a sustained meditation on the Sermon on the Mount and his most famous formulation: "cheap grace" (forgiveness without repentance, grace without the cross) is the deadly enemy of the church, and costly grace, "the grace that costs a man his life," is the only kind worth the name.
From 1940 Bonhoeffer was involved with the Abwehr resistance circle planning Hitler's assassination. Arrested in April 1943 for smaller offenses, he spent two years in Tegel prison before the July 1944 plot's failure exposed his deeper involvement. The letters from prison, published posthumously as Letters and Papers from Prison (1951), contain his most searching theology — on "religionless Christianity," on "man come of age," on what it means to believe in a secular century — written under conditions that give every sentence its weight. Harvey Cox drew heavily on these letters; so did much subsequent 20th-century Protestant theology.