From chapter 5 of Bonhoeffer as Martyr – social responsibility and modern Christian commitment, by Craig Slane, published by Brazos 2004
It was Reformation Sunday 1934 when Bonhoeffer, preaching to this London congregation, distinguished two kinds of churches: the church that aims for success becomes ‘a slave to the powers of this world,’ while the church of faith lives solely by the past deed that God has done in the world, ‘the cross of Golgotha.’ By this particular November Sunday, Bonhoeffer’s mind was already leaping toward the future. Exactly five months earlier he had been approached with the possibility of taking on one of the newly forming seminaries of the Confessing Church, an option he had been weighing together with another: a trip to India where he might actively experiment with Gandhi’s nonviolent resistance based upon Jesus’ Sermon on the Mount. For a time he was, as he put it, ‘hopelessly torn’ between these alternatives. Yet, as different as these two paths may have seemed, either of them might have sufficed to answer what became a burning question for him. Was it possible for a community gathered on the basis of Jesus’ Sermon on the Mount to establish a base of resistance against tyranny?
To put it bluntly, Bonhoeffer was searching for a politically viable form of Christian community. Three years prior he had encountered Jesus’ Sermon on the Mount in a highly personal way. He would testify in 1936 that since that fresh reading of it, ‘everything has changed.’ In his judgement he had ‘become a Christian.’ Shortly before leaving London, he hinted to his brother Karl-Friedrich that communities of this kind could be just the kind of power ‘capable of exploding the whole enchantment and spectre [Hitler and his rule].’ Whether in India or Germany, it would be Bonhoeffer’s growing fascination with this way of Christian life that was searching for concrete expression. When finally he decided to oversee one of the newly forming preachers’ seminaries, he had at his disposal a means by which to negotiate ‘the powers of this world’ and simultaneously to experiment with ‘a community of the cross.’
After its first summer at Zingst, the seminary was moved to Finkenwalde, where, among other scholarly pursuits, Bonhoeffer undertook an intense examination of Matthew 5-7 with his students. Eventually his work culminated in the 1937 publication of Discipleship, at the heart of which stands his exegesis of the Sermon on the Mount. The German title, Nachfolge, contains more than a hint of imitation, of imago Dei and the imitatio Christi. Because of the personal circumstances and sociopolitical pressures out of which the work is written, it is a grave mistake to read it as a timeless, abstract treatment of Christian spirituality. Rather, the existential question exerts pressure from all sides: how must the follower of Jesus live in the Germany of the 1930s, where racism, nationalism, and a growing appetite for war have made themselves friends of the gospel of Jesus Christ.