I recently had the zechus to be by the burial of a very important person. That week I happened to also hear a shiur discussing different aspects of jealousy.
The question is asked how Joseph knew with such confidence that his bones would be intact when Bnei Yisroel left Egypt, Mitzrayim, for he made them swear to take his remains with them many years earlier. The verse proclaims that the bones of the jealous rot. Joseph was the epitome of one who trusted in G-d, a trustwhich rejects the trait of jealousy, and therefore his bones were sure to be intact.
Coming off of Purim, a question is asked why Esther didn’t tell Achasveros about Haman's wickedness at the first party. Why did she wait until the second? The answer is that at the first party she saw Haman was on top of the world, in great happiness, and she felt nothing could topple such joy, simcha. At the next party, it turned out Haman was already humiliated (by having to lead Mordechai as he rode through the city in the king's garments) and therefore his spirit was low, a ripe time to strike.
Happy people are of the type that are not jealous and therefore remain untouchable.
Why does jealousy exist? Only because one doesn’t recognize that everything is exactly as it’s supposed to be. With such probing eyes, one must list their precise blessings and realize that just as it’s important that you have those G-dly blessings, it’s necessary for someone else to have theirs. This leads to a more perfect world.