If hes a TRUE socialistMarxist then YES he would be an atheist per pure MarxistCommunist doctrine believing religion to be an opiate of the masses and counterproductive to the class struggle However its not confirmed that he is an atheist so we better not start speculating even though theres a good chance that he is since hes a socialist Its important to note that his HERITAGE is Jewish though this is more about ethnicity than religion however He is a JEW but doesnt follow Judaism the traditional religion of the Jews