“Who Christ really is, for us today?” This question articulates the intellect and the passion that characterized the life and thought of Dietrich Bonhoeffer (1906-1945). A deeply theological thinker, Bonhoeffer was first and foremost engaged with how the gospel of Jesus Christ is to be lived concretely in the world today. God incarnate in Jesus Christ calls us to the life of discipleship, i.e., to live the Sermon on the Mount. Christ as “the one for others” is also “Christ existing in church-community.” The incarnate God exists “in, with, and under” social relations. Bonhoeffer’s insistence on concreteness, responsibility, freedom, and the time and place for decision committed him to the church and the ecumenical movement. He was no less committed to the world, courageous in the in the time of crisis during which he lived, spoke in his prison writings of the “this-worldliness” of Christian faith.