Is the category of Apikores- a heretic only limited to Jews or even non Jews?
The Sdei Chemed quotes many opinions that forbid quoting from heretics
Thus, is it permitted to quote a heretical gentile that preaches that Judaism is false? Or that there is no world to come. May I quote a wise saying from Muhammad that has nothing to do with theology per se', for since Muhammad denied the truth of the the Torah and its accuracy if he were a Jew he would be classified as an apikores.
(I know that the source for the word apikorus is really the name of a greek philosopher Epicurus)