How did Karl Barth influence Dietrich Bonhoeffer’s theology?

Dietrich Bonhoeffer was significantly influenced by the "theology of revelation" developed by Karl Barth. This influence is evident in Bonhoeffer’s early academic work, particularly his doctoral thesis, Sanctorum Communio (1930), where he sought to integrate sociological and theological perspectives on the church, and in his 1931 work Akt und Sein (Act and Being), which examines the impact of transcendental philosophy and ontology on Christian thought.1

Beyond academic theory, the two theologians were linked through their resistance to National Socialism. Barth spearheaded the theological declaration of the Synod of Barmen in 1934, which provided the foundation for the Confessing Church. Bonhoeffer became a leading spokesman for this movement, which opposed the Nazi attempt to subordinate the church to state ideology and racial doctrines.2