When we are in Christ we are new creations and called to live a new life. In this context Paul tells his readers to not let their anger lead them to sin. Mark explains the difference between righteous anger and the anger that leads us to lose our temper and sin. He encourages us to bring our anger into the light, to allow God to deal with it so that we don't allow the devil to gain a foothold in our lives or those around us.
Mark Rushworth is an Elder of Christ Central Church.