Psalm 37 is a psalm that clearly tells us about evildoers and righteous people. Here is a distinction between these two types of people.
People who like to practice injustice, are those who like to do badly to others, but who do not accept that they do the same with them, but that they ask for mercy for them.
But we can also introduce you to another type of person, he who practices justice, who looks for ways to solve the problems that are presented to him, who loves his enemy, and who does good even for his worst enemy.
The first verse of Psalm 37 begins by urging us not to despair because of the evil ones or to envy those who do bad things because the end of these will be sad. Then it continues to motivate us to do the right thing before God and teach us what will happen to the evil ones.