Bender (1909 – 1994) was born shortly after his father's death. His mother, who came from Lübeck, returned there in 1922 with her four children. He received his first organ lessons in the Marienkirche from Karl Lichtwark and Walter Kraft and became one of the first members of the Lübeck "Singing and Playing Circle" founded by Bruno Grusnick in 1928. 1930-1933 he studied church music in Leipzig, among others with Karl Straube. After the National Socialists seized power in 1933, he first went to Amsterdam and then returned to Lübeck in 1934. Here he studied mainly with Hugo Distler and became his first composition student.
After passing his exam in church music, Bender got a job at St. Gertrud in Lübeck. Here he became involved in the clashes of the church struggle when at the end of 1936 he refused to play the organ at a church service, which was to be held by a pastor belonging to the German Christians, a racist, anti-semitic and Hitler-oriented group in German Protestantism. On New Year's Day 1937, he was arrested and taken to the Sachsenhausen concentration camp, where he was held in "protective custody" until April 20, 1937. In autumn 1937, he received a call as a church musician to the Lambertikirche in Aurich. He was drafted into the Wehrmacht and lost an eye near Leningrad in 1941. In 1944, he was taken prisoner of war by the Americans on the Western front. In captivity, he wrote simple choral sentences for camp services, which were published after his release as "Auricher Singbüchlein" by Bärenreiter-Verlag.