Dietrich was born in Breslau, Germany (now Wroclaw, Poland) into a middle to upper class family, the son of a doctor. At a very young age, before World War I began, he decided to become a minister. His parents supported his decision and he started to spend a lot of time studying the Bible. When he was old enough he attended college and seminary and became a minister. He studied theology in Tubingen and in New York City.
He returned to Germany in 1931, where he lectured on theology in Berlin and wrote several books. A strong opponent of fascism, he fled to London when Adolf Hitler rose to power in 1933. He returned after Martin Niemöller and Karl Barth formed the anti-Nazi Confessing Church, only to have his seminary closed down at the outbreak of World War II. The Gestapo also banned him from preaching. During this time, Bonhoffer worked closely with numerous opponents of Hitler.
During World War II, Dietrich played a key leadership role in the Confessing Church, which opposed the anti-semitic policies of Adolf Hitler. Initially Dietrich fought to gain strong support from the state church against Hitler's treatment of the Jews, but after countless instances of refusal to take action he took the initiative to help start the confessing church. While the confessing church was not large, it represented the only Christian church in Germany that was in opposition to Hitler's practices.
After he realized that diplomatic means to stop Hitler were impossible, he decided that assassination was the only solution. He joined a hidden group of high-ranking officers who were trying to have Hitler killed. Bonhoeffer was arrested in April 1943 after money that was used to help Jews escape to Switzerland was traced to him. He was charged with conspiracy and imprisoned for two years in Flossenbürg. After the unsuccessful attempt on Hitler's life on July 20, 1944, connections of Bonhoeffer to the conspirators were discovered, and he was executed by hanging just three weeks before the liberation of the city. His execution was carried out even though the Germans knew that they were going to lose the war. They did not want the end of the war to save Bonhoeffer from death.
In his theological writings, he states that Christianity should abandon the "religious premise": not the need for explanation of the world or man's need for salvation are central, but the acting in the world in imitation of Jesus.