The reality of this world is that if a person wants to err, he will. Having free choice means that every evil can be rationalized. On the other hand, if a person truly wants to purify himself, he is guaranteed Hashem's help. He therefore employed two main arguments, both of which, says R' Soloveitchik, give us insight into contemporary rebellions against Torah authority. On the one hand, there is choseness of the nation.
Every individual possesses holiness by virtue of being a member of the Jewish people.
This holiness is inherited, and it formed the basis of Korach's ideology. Every Jew is the direct recipient of holiness according to his own unique personal efforts and achievements. Korach did not understand that Moshe possessed a larger measure than others of this second type of holiness. Moshe explained to Korach that there are differences between people. Korach's second argument was that every person has the right to interpret Halacha for himself.