Although we are all the same in not wanting problems and wanting a peaceful life, we tend to create a lot of problems for ourselves. Encountering those problems, anger develops and overwhelms our mind, which leads to violence. A good way to counter this and to work for a more peaceful world is to develop concern for others. Then our anger, jealousy and other destructive emotions will naturally weaken and diminish.
Jealousy is comparison. And we have been taught to compare, we have been conditioned to compare, always compare. Somebody else has a better house, somebody else has a more beautiful body, somebody else has more money, somebody else has a more charismatic personality. Compare, go on comparing yourself with everybody else you pass by, and great jealousy will be the outcome; it is the by-product of the conditioning for comparison.
Mentally, physically and emotionally we are the same.
We each have the potential to good and bad and to be overcome by disturbing emotions such as anger, fear, hatred, suspicion and greed. These emotions can be the cause of many problems.
On the other hand if you cultivate loving kindness, compassion and concern for others, there will be no room for anger, hatred and jealousy.