כל מחלוקת שהיא לשם שמים סופו להתקיים ושאינו לשם שמים אין סופו להקיים. איזו מחלוקת לשם שמים זהו מחלוקת הלל ושמאי, ושאינו לשם שמים זהו מחלוקת קרח וכל עדתו. (אבות ה' יז')
Every dispute that is for the sake of Heaven will endure, however any that is not for the sake of heaven will not endure--
What is a case of a dispute for the sake of Heaven? The disagreements between Hillel and Shamai. What is a case of a dispute not for the sake of Heaven? The argument of Korach and his gathering...
The Malbim points out a discrepancy in the Mishna. In the example of Hillel and Shamai, both parties are mentioned. Korach and his gathering, however, were only one side of their conflict. It should have said: a dispute not for the sake of Heaven is like Korach and Moshe. Why doesn't the Mishna give a more balanced description?
The Malbim offers an eye-opening insight. How does one determine the motivation behind a conflict? You can tell whether the two sides are fighting for the sake of Heaven -- or not -- by the way each party conducts itself internally.
Hillel and Shamai, though they disagreed, respected each other because both were trying to understand the Will of Hashem. In Korach's camp, however, there was fighting even among themselves. Each person had their own personal reason to fight with Moshe. Korach thought he should be the head of his family, Dasan, Aviram and On thought that Reuvain should retain the firstborn rights, the two-hundred-fifty heads of the Sanhedrin thought they should have part in the decision making.
With this approach, the Mishna reads perfectly: What is a dispute for the sake of Heaven? The disagreements between Hillel and Shamai. What is a dispute not for the sake of Heaven? The argument of Korach -- and his gathering! May Hashem give peace among us and not allow our personal honor and interests to involve us in any dispute.