If you convert from Judaism, you cease to be a Jew. If you start an atheist cult dedicated tothe cultural genocide of Jews, you are not a Jew. Marx was not a Jew after 5 and was an open antisemite.
In its perfected practice, Christian egoism of heavenly bliss is necessarily transformed into the corporal egoism of the Jew, heavenly need is turned into world need, subjectivism into self-interest. We explain the tenacity of the Jew not by his religion, but, on the contrary, by the human basis of his religion – practical need, egoism.On The Jewish QuestionSince in civil society the real nature of the Jew has been universally realized and secularized, civil society could not convince the Jew of the unreality of his religious nature, which is indeed only the ideal aspect of practical need. Consequently, not only in the Pentateuch and the Talmud, but in present-day society we find the nature of the modern Jew, and not as an abstract nature but as one that is in the highest degree empirical, not merely as a narrowness of the Jew, but as the Jewish narrowness of society.
Once society has succeeded in abolishing the empirical essence of Judaism – huckstering and its preconditions – the Jew will have become impossible, because his consciousness no longer has an object, because the subjective basis of Judaism, practical need, has been humanized, and because the conflict between man’s individual-sensuous existence and his species-existence has been abolished.
The social emancipation of the Jew is the emancipation of society from Judaism.