Why does Danny consider Reuven and his classmates "apikorism"?

Reuven is not Hasidic. His father is an Orthodox Jew, and Reuven attends a yeshiva, a Jewish school, in Crown Heights, where there are Hebrew studies in the morning and English studies in the afternoons. Apikorism are those who do not follow Jewish law and practice. Danny regards anyone who does not share the narrow beliefs of the Hasidic sect to which he belongs as an apikoros.Realizing that Danny's team regards the game as a war between themselves, the righteous believers, and the sinful apikorism, Reuven starts to feel hatred for Danny. There is ill-feeling between the two teams as the game continues. It starts to resemble a war.