"To abandon yourself to rage is often to bring upon yourself the fault of another." St. Agapetus I

No wonder Jesus spoke against the sin of rage, while at the same time urging forgiveness from the heart. Your rage affects you more than the other. To combat this, St Paul urges us not to let the sun go down on your anger, lest you give the devil an opening. The initial anger is an emotion. The sustained anger is a sin. Take control of our emotion, otherwise it will contol us.