The third of seven keys to Bonhoeffer’s house is living according to the Sermon on the Mount.
The German university system of Bonhoeffer’s time did not emphasize the Sermon on the Mount, Jesus’ manifesto on how to live as a disciple of His. In fact, some of its leaders viewed the Bible like a history book; interesting; but not an invitation into relationship with the Creator in a deep personal way, captivating the human heart with undying love leading to giving oneself fully in obedience to His leadership.
Dietrich chose theology as his major of choice, entered the university of Berlin, and came under the tutelage of Adolf Van Harnack. “His [Adolf] approach to the Bible was limited to textual and historical-critical analysis, and had led him to conclude that the miracles it described never happened, and that the gospel of John was not canonical.” So Bonhoeffer learned how to do this brilliantly while simultaneously being discipled by Karl Barth who viewed the Bible as God’s word and saw the need for God to reveal Himself to its readers. “Barth was the principle figure of challenging and overturning the German historical-critical approach pioneered at Berlin University… Barth stressed the transcendence of God, describing him as “wholly other,” and therefore completely unknowable by man, except via revelation… Bonhoeffer agreed with Barth, seeing the texts as ‘not just historical sources, but [as] agents of revelation,’ not merely ‘specimens of writing, but sacred canon.’”
Combined with the influence of these two elders of Bonhoeffer, a peer steered him in the direction of the Sermon the Mount during his first visit to America in 1930-31. “[Jean] Lasserre spoke often about the Sermon on the Mount and how it informed his theology. From that point forward it became a central part of Bonhoeffer’s life and theology, too, which eventually led him to write his most famous book, The Cost of Discipleship.” The German name for this book is Nachfolge, meaning following. We know the book today as the Cost of Discipleship. “The German title…captures Bonhoeffer’s intention: Christian life and ministry require following Jesus, whatever that means at any concrete moment, according to what the Bible teaches.”
The book finds some of its moorings on the first ten or so chapters of Matthew, which includes the Sermon the Mount in Mathew 5-7. The church is composed of people who are saved by God’s grace in Jesus Christ through faith. This is not of ourselves but a gift from God to us. Followers of Jesus are called by Jesus, not the other way around. Jesus says to His disciples “follow Me” (Matthew 4:19). He calls His followers to wholehearted obedience, laying out His values summed up with the imagery of building a house on a firm foundation (Matthew 5-7). He sends out His followers to testify of God’s kingdom, confirming it with miracles of healing and deliverance (Matthew 10). They are to train others in His values and pray for more followers (Mathew 5:19-20; 9:37-38).
More specifically in what is know as the Sermon on the Mount, Jesus teaches on eight heart postures (beatitudes) (5:3-12), six temptations to resist (5:21-48) while seeking full obedience (5:43-38), living in the four rhythms of prayer, fasting, giving, and forgiving (serving is inherent in these) as the way to stay in humility/dependence (6:1-18), and to keep us focused on seeking first God’s kingdom and righteousness over providing for ourselves in our own wisdom (6:19-33). We live this way without criticizing and comparing with others (7:1-6) as we trust Jesus to intervene in our relationships (7:7-12) as we wholeheartedly follow Him along the narrow way (7:13-14), and discern false grace messages (7:15-20). Our obedience will be tested (7:21-27), we will impact society (5:13-16), be great in God’s eyes (5:19), receive treasures in heaven (6:19–20) and live in this age with our heart exhilarated in His grace (6:22-23).
At some point during his stay in America or shortly after, a deep change happened in Bonhoeffer that set him on a fierce pursuit of Jesus and His Sermon on the Mount. A letter he wrote in 1936 describes that change: “I plunged into work in a very unchristian way. An… ambition that many noticed in me made my life difficult…Then something happened., something that has changed and transformed my life to the present day. For the first time I discovered the Bible… I had often preached. I had seen a great deal in the Church, and talked and preached about it—but I had not yet become a Christian….I know that at that time I turned the doctrine of Jesus Christ into something of a person advantage for myself…I pray to God that that will never happen again. Also I had never prayed or prayed only very little. For all my loneliness, I was quite pleased with myself. Then the Bible, and in particular the Sermon on the Mount, freed me from that. Since then everything has changed. I have felt this plainly, and so have other people about me. It was a great liberation. It became clear to me that the life of a servant of Jesus Christ must belong to the Church, and step by step it became plainer to me how far that must go. Then came the crisis of 1933. This strengthened me in it. Also I now found others who shared that aim with me. The revival of the church and of the ministry became my supreme concern….My calling is quite clear to me. What God will make of it I do not know…I must follow the path. Perhaps it will not be such a long one (Philippians 1:23). But it is a fine thing to have realized my calling…I believe its nobility will become plain to us only in the coming times and events. If only we can hold out.”
Back from America under the tightening reigns of Hitler in Germany, Bonhoeffer continued to work out his thoughts on discipleship. A letter he wrote on September 11, 1934 to Eriwn Sutz details this: “I am hopelessly torn between staying here [London], going to India and returning to Germany to take charge of a preachers’ seminary shortly to be opened there. I no longer believe in the university, and never really have believed in it—to your irritation. The entire education of the younger generation of theologians belongs today in church cloister-like schools, in which pure doctrine, the Sermon on the Mount and worship are taken seriously—as they never are (and in present circumstances couldn’t be) at the university [because the Nazi government was increasingly censoring and controlling every area of society].”
On the cusp of leading the illegal seminary of the Confessing Church, Bonhoeffer wrote a letter to his elder brother Karl-Friedrich to tell him about it. The contents reveal again how the Sermon on the Mount guided him. “I think I am right in saying that I would only achieve tree inner clarity and honesty by really starting to take the Sermon on the Mount seriously. Here alone lies the force that blow all of this idiocy sky-high—leaving only a few burnt our shells behind. The restoration of the church must surely depend on a new kind of monasticism, which has nothing in common with the old but a life of uncompromising discipleship, following Christ according to the Sermon on the Mount. I believe the time has come to gather people together and do this.”
Bonhoeffer pushed against the cultural current of Christianity of his day that was not producing, in his evaluation, wholehearted disciples of Christ. “[He] had in mind a kind of monastic community, where one aimed to live in the way Jesus commanded his followers to live in his Sermon on the Mount, where one lived not merely as a theological student, but as a disciple of Christ. It would be an unorthodox experiment in communal Christian living, in the ‘life together’ as Bonhoeffer would so famously write. No one in the Lutheran tradition had ever tried such a thing. The knee-jerk reaction away from anything that smacked of Roman Catholicism was strong, but Bonhoeffer had long before moved past such parochialism and was willing to bear criticisms. He felt that Lutheran Christianity had slid away from Luther’s intentions, just as Luther felt that the Roman Catholic Church had moved away from St. Peter’s and, more important, from Christ’s. Bonhoeffer was interested in a Holy Spirit-led course adjustment that hardly signaled something new….Bonhoeffer’s attitude was that it [Christianity] must be made real to the man on the street, and that was where the church was failing. That’s what this experiment on the Baltic seashore was all about.”
Bonhoeffer trained around 181 people over five years and the majority of them fought and died in World War 2. Though his training experiment appears meager and unfruitful in the world’s eyes and in his generation, God is highlighting his labors. He is highlighting them to us in this generation to model as a way to live victoriously in our generation and as we head toward the end of this present age.