This is why he is called man the higher animal. He is intrinsically engineered to desire all the good things for himself while others can perish. And when others get the good things which he may or may not have, he begins to resent them and wish that he had it and not them. But why does he want others to remain below and continue to depend on him?
Jealousy is defined as the resentment towards someone for a perceived advantage or superiority they hold. If the effect of jealousy is properly investigated, it would be discovered that the jealous man mutilates himself psychologically. This is why he is often moved to commit physical and (even spiritual) harm to the object of his jealousy. A foolish man is the man who acts negatively on his jealousy. Desiring good things for oneself is not bad; it is the outcome that determines whether it is or not.
The intelligent man understands that the progress and success of his neighbour reduces his own burden. He becomes free and is less bothered with the difficulties of those around him. His brother’s wife does not call him lamenting and beseeching that he provides money for his niece’s and nephew’s education, his friends do not call to ask for food, his colleagues do not call every time to ask for instruction. He is more free when he helps others become better and independent.
Once it was reported that when a newspaper reporter interviewed a farmer who grew award-winning corn each year he entered his corn in the state affair, it was revealed that the farmer shared his seed corn with his neighbours. Perplexed, the reporter asked, ‘How can you afford to share your best seed corn with your neighbours when they are entering their corn in competition with yours each year?’ The farmer smiled knowingly and explained, ‘The winner picks up pollen from the ripening corn and swirls it from field to field. If my neighbours grow inferior corn, cross-pollination will steadily degrade the quality of my corn. If I am to grow good corn, I must help my neighbours grow good corn.’
Man must learn not to create troubles for himself where there should be none. It is so funny to find him chasing the wind with energy that should have been directed towards accomplishing great deeds. Indeed, he can use the time he spends fusing about the success and progress of his fellow man to think of innovative concepts or even go humbly to his object of jealousy and ask how he could accomplish such a worthy feat that makes him jealous.
The same reason for taming other animals must be extended to man in this regard. He is sometimes ignorant of certain truths which must be brought to his awareness. He can and must be taught. This is how he must be tamed. A continual censure without revelation of the truth would only lead to a vexation of spirit and aggravate this vice. Having been taught and shown the truth and the consequences of accepting or not, he must be allowed to make his own decision.
Man must continue to work on his nature else he stands a chance of moving from the best and most lovely creation of God to the worst and most depraved. It would do him great good if he recognises and accepts the fact that desiring good is an intrinsic part of him and then take control.
 Advanced Learners Dictionary, s.v. jealousy