This, at first glance, is a very strange passage to find in the Bible. We must remember that in this book, Solomon is speaking from a worldly point of view. There cannot be over much of the righteousness which is by faith. There is not a righteous man on earth who does what is right and never sins. He goes on to point out a couple of cases where he finds a lack of wisdom.
Sin is always a case of failing to put godly wisdom into practice.
We sin when we knowingly go against God s Word. We all sin, and so there is in all of us much room for improvement concerning putting into practice of godly wisdom. Second, Solomon finds a lack of wisdom in people who get upset at what others say. We all say stupid things at unguarded moments. Therefore, show some forgiveness for those who say stupid things about you.