There is a book written by a Jewish psychiatrist Dr. Josef Berke which is called the Tyranny of Malice.
In other words, his entire book is about the tyranny of jealousy and he asserts that to ignore it, is to ignore the past, to misunderstand the present, and to endanger the future.
Jealousy lies at the heart of all evil.
The cause of the first murder – in fact the cause of mans downfall (for wasn’t the satans, through the snake, or embodied in it, causing man to sin through the snakes appeal “God desire not that you should eat from the tree of knowledge, lest you become like God.”)
Now the reason I call jealousy the monster within, is, because as our sages teach us, people are jealous over anything besides their student or child (for then it is themselves.)
But in a simple twist, we can understand the true cause of this monster and hence understand its remedy.
Life consists only of two basic elemental stages which man is in.
Fear / anger . hate
Being in love feels good which is why people tend to be in it
However what happens when a person gets resentful “it isn’t fair” etc. etc. then as Rabbenu Bechayah writes, a person cannot hold love and fear . hate in their hearts at the same time, so like a seesaw, either love is in the air or hate, anger, resentment is.
Now that wouldn’t be so terrible if not for the following fact.
Jealousy is the state in which man will descend into if s/he is not in a state of love.
Why does man not get jealous of his student or son?
Because he is his student or son!
So when we are in love and identify, see ourselves in others, we are not jealous of them.
Rather when we are in fear or anger or revenge mode, God forbid, it is then that we desire to destroy the happiness of he, who is in a state of love.
For example, the other day I was walking with my brother and someone said an antisemitic comment to us.
Looking at the persons pickup truck I was not surprised to see a battered up barely working truck.
You see a person whose life is good has no jealousy of another’s.
It is a person whose life is dismal (now this often refers not to the outside, rather a person’s self esteem etc. etc.) it is s/he who picks on another, trying to lower their happiness to temporary fill their own abysmal self-image with a temporary fix of grandeur.