Many are angry at life because they have created a reality based on their past negative experiences, also creating the belief that this is who they are and that this is what they were meant to be.
The best we can do is understand, and project a level of compassion because now you know that even though these people have many difficulties within themselves there is still some good in them weather they realize it or not.
But you will also encounter those that are simply not interested in changing their ways. Simply move on and if possible out of the environment where these people are.
Sometimes you have to be compassionate enough to allow them to find their own way.
Dealing with people who put you down is not something that anyone can totally avoid. As long as you’re part of groups at work, school, social gatherings or even at home; beliefs will certainly clash.