It was one of the very first questions that God asked man, and it may well be one of the most important questions any person can be asked. The very first mention of anger in the Bible involved Cain in Gen 4:5, and God's response was immediate, found in Gen 4:6 - "Why are you angry?"
Anger is not wrong in and of itself, and it does not always lead to sinful wrong-doing. Psalm 7:11 says that God Himself expresses His anger every day. Jesus was without sin, but Mark 3:5 says "He looked around at them in anger, deeply distressed at their stubborn hearts." Paul acknowledges the difference between the feeling of anger and the expression of anger is a sinful way when he says "In your anger do not sin." (Ephesians 4:26)
However...
Anger should not characterize the Christ follower (Colossians 3:8). Anger should be difficult to come by in the Christ-formed character (James 1:19), not common. Anger is a work of the flesh, not of the spirit (Ephesians 4:31). And Jesus himself says in no uncertain terms, "But I tell you that anyone who is angry with his brother will be subject to judgment." (Matthew 5:22)
Legion are the ways that anger abides and shows itself: Bitterness. Malice. Unforgiveness. Rage. Violence. Filthy Language. Revenge. Jealousy. Grudges. Judgments. Sarcasm. Treachery. Gossip. Lying. Slander. Fury. Manipulation. Outbursts. Accusations. Quarrels. Hate.
All of these get individual attention and condemnation in scripture. Anger kills. So let us learn to kill anger.