Korach is a tragic figure in a tragic story. At first glance his platform of "the entire assembly all of them are holy and Hashem is among them" is valid, however the conclusion of the verse "why do you exalt yourselves over the Congregation of Hashem" (Bamidbar 16:3) is most perplexing. How could he question the suitability and eligibility of Moshe and Aaron to lead the Jewish people? The Torah testifies that at the Yam Suf, "they had faith in Hashem and in Moshe as his servant" (Shemos 14:31.) In addition, when Hashem tells Moshe of the initial plan at Sinai, He informs him "behold I come to you in a thickness of the cloud, so that the people will hear as I speak to you, and they will also believe in you forever" (ibid 18:3.) How is it possible in that context that Korach challenges Moshe's authority?
Moreover, Korach was already an accomplished "somebody". He was wise, wealthy, among the chosen few that carried the Holy Ark (Medrash Rabbah, Bamidbar 18:3), and was endowed with prophecy, so what led him to this folly? Rashi gives two answers.
The first answer is given in his commentary on the first verse, citing the medrash that Korach was motivated by jealousy. He was disappointed that he was not selected to be the head of the entire Kehas families in shevet Levi. He accused Moshe of selecting a different cousin, Elitzafon the son of Uziel, on his own, when in reality the designation was made by Hashem himself (ibid 18:2.)
Interestingly, Rashi provides a second reason that led Korach astray. Rashi adds "his eye led him to error" (Bamidbar 16:7.) He saw prophetically a great chain of distinguished descendants coming from him, including the prophet Shmuel. In addition, he saw no less than twenty four groups of rotations of his descendants serving a week each in the Beis Hamikdash, and thus reasoned that these extraordinary progeny will ensure his survival in his confrontation with Moshe.
Is Rashi providing two different motives to explain Korach's behavior? Are these explanations in sync or in conflict with each other?
I would like to suggest that in reality they are one and the same. Rashi's first explanation defines the negius (bias) that consciously or subconsciously consumed Korach. Once he convinced himself that he was slighted and wronged, once his desire for honor consumed him, then, in keeping with the Torah's description of the effects being bribed has on one's judgement, Korach now viewed everything through tinted glasses. He did see correctly that Shmuel and twenty four prestigious watches would descend from him. However, unlike his reading of self-aggrandizement and glory, the Rabbis teach that he warranted this special progeny through his sons who did teshuvah, and because of the kiddush Hashem (the sanctification and glorification of Hashem's name) that emerged from those buried alive proclaiming "Moshe is true and his Torah is true, and we are liars" (Bava Basra 74a).
The Mesilas Yesharim (chapter 11) teaches that the most toxic bias is the lust for honor. He cites the Zohar (3:158) that explains the downfall of the meraglim (the 12 spies that were sent to spy out the land of Israel) who returned with the most devastating and damaging report. The exact question that was asked above regarding Korach may be asked regarding these spies. The Torah testifies "they were all distinguished men" (Bamidbar 13:3) and Hashem had assured them it was "a good and spacious land" "flowing with milk and honey" (Shemos 3:8.) How, then, could they return with a report that contradicted G-d himself? The Zohar explains that their fear of losing their positions of leadership which would not be renewed in the environment and setting of the land of Israel. Thus, to retain their honorable stations they too wore the tinted glasses of negius-bias and their report was couched to ensure they will retain the status-quo in the desert.
The third powerful example of negius is that of Yerovom ben Nevot who was chosen by Hashem to lead the ten tribes, the Kingdom of Israel, which was taken away from King Solomon after his death. Yerovom was fearful that if his subjects would travel to the Bais Hamikdash three times a year to celebrate the pilgrim festivals, they would become followers of Rechavom King of Judah. Yerovom therefore forbade his people from going to Yerushalyim and established golden calves in the north and south of the land. Hashem provides the opportunity for Yerovom to repent by assuring him that were he to repent, he would not only go to Gan Eden upon his passing, but would even have the privilege to stroll with Hashem himself and King David. Faced with this opportunity Yerovom asked but one question: who is first in this procession? He understood that Hashem would lead, but who is next? When Hashem told him he would have to take a back seat to King David, he responded "I am not interested" (Sanhedrin 102a.) Such is the drive and power of the lust for honor. Too often we don't see it in ourselves, but we can and do see it in others.
The mishna teaches, "accept a teacher upon yourself, and acquire a friend for yourself" (Avos 1:6.) I would like to suggest another reason for this teaching. We are taught that adom karov l'atzmo-a person is naturally biased in favor of himself (Sanhedrin 10a.) We are too often quick to see the faults and shortcomings of others, but not our own. We can see through the next one; we can connect the dots of their rejection, hurt, slight, humiliation, and their subsequent actions that often deviate from their otherwise pristine character. Be that friend. Point out the negius-bias that is obstructing their clear thought perspective and vision. A good friend is a good listener.