The message of פרשת קרח that seems to really stick out, is the danger of what jealousy can bring. Korach had wealth and honor but did not have the position held by Moshe and Aharon.
The אור החיים הקודש speaks about how one should focus on love and stay away from שנאה, or hatred. He explains that there are many reasons why one may be overcome with hatred towards another person. Most of them are not justified and some are able to be remedied. For example, if one caused another monetary loss or bodily harm, he can fix it with compensation for the loss or an apology. But in the words of the אור החיים, a שנאה מחמת קנאה, hatred because of jealousy, is by far the most difficult to overcome.
One needs to realize how קנאה, jealousy, is a horrible, negative, character trait. It prevents an individual from being happy. No matter how much he has and how content he should be, the focus and obsession with another person, gives him no peace of mind.
We must learn from the mistake of Korach, and not look at others and learn to be content with what we have.