From today's devotional
This psalm begins extolling the joys of obeying God and refusing to listen to those who discredit or ridicule him.
Our friends and associates can have a profound influence on us, often in very subtle ways. If we insist on friendships with those who mock what God considers important, we might sin by becoming indifferent to God's will. This attitude is the same as mocking.
Do your friends build up your faith, or do they tear it down? True friends should help you to draw closer to God, not hinder your relationship with him.