A lot of harm can come from a bad influence in your life. It pays to be careful about the company you keep. We should choose our friends wisely, because they tend to have an impact on our words and actions, either for the better, or for the worse.
“Do not be misled: ‘Bad company corrupts good character’. Come back to your senses as you ought, and stop sinning; for there are some who are ignorant of God—I say this to your shame.”—1 Corinthians 15:33-34.