On one hand, from a Biblical perspective, Korach's actions are sinful because they contradict the explicit will of God. However, with close reading of classical texts, we can identify some of the more nuanced elements of the parasha, and the multifaceted nature of Korach's wrongdoing.
The parasha begins with vague wording, "Korach took," but it is not clear what he took or how he took it. The rabbis, in midrash Numbers Rabbah 18:2, propose a theory of what Korach took and how he acquired it:
In English, this line has been translated this way (Soncino):
ויקח אין ויקח אלא משיכת הדברים רכים שנמשכו כל גדולי ישראל והסנהדראות אחריו
KORAH... TOOK. The expression taking, clearly denotes drawing along with persuasive words, all the chiefs of Israel and the Sanhedrin having been drawn after him.
In essence, the chiefs and judges of Israel were taken with his speech. The English translation, in an effort to be clear, obscures some nuance. According to the midrash, Korach draws people in with הדברים רכים, words that are soft. This could mean that he had a unique ability to draw people in with a soft voice instead of loud demagoguery, contrary to popular depictions of this Biblical anti-hero. It could also mean that he spoke words that were easy to digest, as opposed to the tough realities that were being presented by Moses and Aaron. Eager for easy answers and accessible solutions, the leaders of Israel were willing to follow Korach instead of Moses and Aaron.
Korach not only compelled people with his words, he also took away something from them -- their good sense and their understanding of truth. In Jewish law, there is a prohibition against גניבת דעת, g'neivat da'at, or stealing someone's knowledge. For example, if you walk into someone's store and take up the owner's time asking questions only to compare prices but with no real intention of buying anything from him, this is g'neivat da'at. Deception is a form of theft, and just as much a prohibition of Torah law as stealing an object from them.
We live in a world of complicated problems, as Americans, Jews, and global citizens. There are a variety of individuals, who occupy all points on the political spectrum, who claim to present a simple version of reality and solutions that require no sacrifice. Korach was a compelling speaker who spoke of receiving privileges, but never about mitzvot, commandments, the hard prices we pay for freedom and privilege.
There are two parties who were responsible for the sin of Korach -- Korach himself and the people who allowed their better judgment be stripped of them. This week let us be resolute and critical of all the messages that are out there for the taking. Is what I am hearing overly simplistic? Does it require nothing of me? Does it contradict the advice of the people I trust? When we speak, do we give the full truth with all of its complexities and the limits of our own power of speech and action? Let us learn from the story of Korach to be intellectually and spiritually strong in our presentation and understanding of Truth.