From the Sfas Emes blog
In this week’s parsha Moshe Rabbeinu says to Korach, “ הַמְעַט מִכֶּם כִּי־הִבְדִּיל אֱ-לֹהֵי יִשְׂרָאֵל אֶתְכֶם מֵעֲדַת יִשְׂרָאֵל ... וּבִקַּשְׁתֶּם גַּם־כְּהֻנָּה׃ לָכֵן אַתָּה וְכָל־עֲדָתְךָ הַנֹּעָדִים עַל ה׳ .../Is it not enough for you that the God of Israel set you apart from the community of Israel … that you also seek the priesthood? Therefore, you and your entire company assemble against God!” (Bamidbar 16:9-11) The Sfas Emes points out that the word “therefore” does not seem to have any meaning. It does not seem to flow from the preceding statement. What is the meaning of this pasuk?
A true understanding of Korach’s sin will shed light on this pasuk. Korach thought that Aharon received the priesthood based on his own merits. Korach argued that, “... כָל־הָעֵדָה כֻּלָּם קְדֹשִׁים .../… the entire congregation is holy …” (Bamidbar 16:3) and in fact there may be others who are more worthy than Aharon. In fact, in his arrogance, he thought that he himself was worthy of the priesthood.
Moshe Rabbeinu responded, “... אֲשֶׁר־יִבְחַר ה׳ הוּא הַקָּדוֹש .../… the man whom god shall choose is the holy one …” (Bamdibar 16:7) The Sfas Emes explains that both Korach and Moshe Rabbeinu were correct. However, Moshe Rabbeinu is pointing out to Korach that the holiness of the nation is divinely decreed and not based on individual merit. Furthermore, the holiness of the nation came through Moshe Rabbeinu. God instructed Moshe at Mount Sinai, “... וְקִדַּשְׁתָּם הַיּוֹם וּמָחָר .../… You shall make them holy today and tomorrow ...” (Shmos 19:10)
Korach forgot that his own holiness and the holiness of the entire nation came from God and that God gave special levels of holiness to the priests, the Levites and to the rest of the nation. If he had understood this, there would have been no place for his argument or his jealousy. Even Korach understood that a divine decree does not need to fit into Korach’s view of justice. He thought that God gave Aharon the priesthood based on Aharon’s merits. According to his understanding he had a good case. Korach was more deserving, in his own eyes, than Aharon. Korach’s jealousy was obviously totally misplaced.
With this understanding the meaning of the word “therefore” becomes clear. By asking for the priesthood, Korach showed that he thought Aharon received the priesthood based on his own merits rather than as a divine decree. It wasn’t fair. He, in his own eyes, was more deserving than Aharon. Therefore, he and his people assembled against God.
This is the meaning of the Chazal which explains the first few words of our parsha, “וַיִּקַּח קֹרַח .../Korach took.” (Bamidbar 16:1) The Torah does not tell us what it is that he took. Chazal explain that he took for himself. He took the holiness that God had bestowed on others, for himself.
This also explains the pasuk that the Midrash brings and says is referring to Korach, “אָח נִפְשָׁע מִקִּרְיַת־עֹז .../A rebellious brother (separates himself) from a strong city …” (Mishlei 18:19) The Midrash explains that the strong city is a metaphor for the strength of the Torah. This strength came to him from Moshe and Aharon. By separating himself from them, he unwittingly separated himself from the very source of his own strength.
The key point here is that the Jewish nation is holy because God decreed it, not because of anything we have done or have not done. Furthermore, there divinely decreed levels of holiness within the nation. A priest is holier than a Levite who, in turn is holier than the rest of the nation. Does this mean that there are limits as to how holy I can become? No matter what I do, I who am neither a priest nor a Levite, can never attain their holiness.
On the face of it, this seems like an unfair distinction. After all, a wicked priest and a righteous member of the nation who is not a priest is not only possible, but has happened. The answer is that God put each of us here to accomplish a personal mission within the context of the nation. As a non-priest, my mission is inherently different, not less important, just different, than the a priest’s. The goal of each of us is to discover his mission and achieve it to the best of his ability with God’s help. This is the lesson that we can take from Korach. Korach had a mission which his arrogance caused him to lose sight of. The results were catastrophic.
By concentrating on our own mission, instead of someone else’s and asking God to help us discover and live it, we are already on our way to attaining that goal.
 Sanhedrin 109b, Zohar 3:176a
 Bamidbar R. 18:14