Proverbs 17:4-5 “One who acts wickedly pays attention to evil counsel; a liar listens to a malicious tongue. The one who mocks the poor has insulted his Creator; whoever rejoices over disaster will not go unpunished.”
A person who acts or speaks wickedly is more likely to listen to those encourage those actions. The opposite is probably true as well. A person who listen to gossip or to those who encourage evil deeds is much more likely to do those things themselves.
1 Corinthians 15:33 “Do not be deceived: ‘Bad company corrupts good morals.'”
Some examples of evil speaking are mocking those who are less fortunate than we are, or rejoicing when something bad happens to someone else. Aren’t we allowed to rejoice when the ungodly are judged? Is there a difference between feeling vindication and rejoicing? At the heart of the matter is probably the realization that “there, but for the grace of God, go I.” The saying is probably about 500 years old, but is perhaps inspired by Paul:
1 Corinthians 15:10 “But by the grace of God I am what I am, and his grace to me has not been in vain.”
There is also the reminder from Jesus that by ministering to the poor who are believers, we are ministering to Him:
Matthew 25:40 “And the king will answer them, ‘I tell you the truth, just as you did it for one of the least of these brothers or sisters of mine, you did it for me.’”
And Obadiah reminds us to never rejoice over the misfortune of believers:
Obadiah 12-15 “You should not have gloated when your relatives suffered calamity. You should not have rejoiced over the people of Judah when they were destroyed. You should not have boasted when they suffered adversity. You should not have entered the city of my people when they experienced distress. You should not have joined in gloating over their misfortune when they suffered distress. You should not have looted their wealth when they endured distress. You should not have stood at the fork in the road to slaughter those trying to escape. You should not have captured their refugees when they suffered adversity. For the day of the LORD is approaching for all the nations! Just as you have done, so it will be done to you. You will get exactly what your deeds deserve.”
We see here how the gloating turns into evil actions, and that the just recompense of their evil deeds is waiting for them.