Isak Julius Samuel was born in Freudenberg, Germany as the son of Samuel Samuel (1862-1935) and wife Ida (born Weil, 1868-1942). During World War I and after, 1915-1922, he studied in Trier, at the Kaiser Wilhelm Gymnasium. In 1925 he moved to Berlin, where he started his studies as a regular student at the Hildesheimer Rabbinerseminar, from which he was ordained as a Rabbi in 1929. The following year, he married Henriette Pollak (born 1907 in Berlin). That same year he was offered the position as rabbi in Oslo. Here the couple's three children were born; Aron Elchanan (born 1932), Kaja Esther (born 1933) and Amos (born 1939). 

Shortly after his arrival to Norway, Samuel gained full knowledge of the Norwegian language. His sermons and lectures on Judaism and other subjects were given in Norwegian, and he also lectured on various topics to the Norwegian public in general. On the 9th of September 1942 Samuel was arrested by the German security police and incarcerated at Grini prison camp. From here he was deported on the 20th November 1942. 3 weeks later Isak Julius Samuel was killed in Auschwitz. His wife and children managed to escape to Sweden and thus survived the Holocaust.