[nickcarraway]

Incorrect. Karl Marx was Lutheran, until he became an atheist. He was born to two Lutherans, and raised in a not-very-religious Lutheran home.

[TSchmereL]

No, sir, you are incorrect. Karl Marx was Jewish according to the Halacha, Jewish law.

Karl Marx's parents, Hirschel Mordechai and Henrietta Marx, were Jewish. His parents converted to Christianity so that his father could pursue his career as a lawyer in the face of Prussia's anti-Jewish laws.

Karl Marx was not a religious Jew, but he was Jewish.
Same with Noam Chomsky and Norm Finkelstein--not religious Jews, but Jewish.