(Proverbs 4:16 KJV) For they sleep not, except they have done mischief; and their sleep is taken away, unless they cause some to fall.
The first thirteen verses of this chapter are singing the praises of wisdom then in verse 14 it turns to warning against making the wrong choices. Here Solomon points out to us that there are people who glory in their wrong choices. There are people who rejoice in “evil” (7489a).
As much as we want to be positive, think the best of people and not judge, we are surrounded by people who thrive on evil. They cover it up well. They may not even see it themselves. But they are tense with frustration if they have not done something to fight the cause of God.
So? Live with caution. Be aware. And rejoice because you serve the righteous God.