Originally, the comment was a "common sneer aimed at people" who had "thrown off the faith of their forefathers and adopted the garb of their Fatherland".
By the twentieth century, the German Jews had reached a state of Bildung und Besitz (i.e., cultivation and wealth).
Thus, by combining German bourgeois practice and Jewish heritage, they formed a German-Jewish identity that balanced integration and tradition.
Kurt Singer (born 1885, died 1944 in Theresienstadt concentration camp), was a conductor, musician, musicologist, and neurologist.
She wrote that her family kept a kosher home, attended synagogue, and was a part of Berlin's tight-knit Jewish community.
Julius Hirsch, who was convinced the Nazis would not harm him as he had fought valiantly in the Imperial German Army for four years (for which he had been awarded the Iron Cross) and had played for the Germany national football team.
Fritz Haber, a German-Jewish chemist who in 1918 received (together with Carl Bosch) the Nobel Prize for Chemistry for the invention of the Haber-Bosch process, a key ingredient for the production of modern fertilizers;[12][13] It is estimated that one-third of annual global food production uses ammonia from the Haber–Bosch process, and that this supports nearly half of the world's population.
However, Haber, a known German nationalist, is also known for his work weaponizing chlorine, and he led the team developing gases used for chemical warfare in World War I.