Do not let the sun go down while you are still angry…Ephesians 4:26
Anger is an overwhelming part of our cultural, political, and personal rhetoric. Should we be concerned, or is anger an appropriate response to injustices?
God demonstrates the purpose of anger: to reveal an injustice or sin. God detests people who become rich at the expense of the poor (Deuteronomy 25:13-16), declare the innocent to be guilty (Proverbs 17:15), and murder the innocent (Proverbs 6:17). Holy anger is an appropriate response to something broken that needs fixing.

Lovis Corinth’s Cain and Abel
Cain is an example of anger that has been distorted by jealousy and self centeredness. Cain and Abel offer sacrifices to the Lord. Abel’s sacrifice is found pleasing; Cain’s is not:
So Cain was very angry, and his face fell. The Lord said to Cain, “Why are you angry, and why has your face fallen? If you do well, will you not be accepted? And if you do not do well, sin is crouching at the door. Its desire is for you, but you must rule over it. (Genesis 4:5-7)
God encourages Cain to act rightly and not to trust his anger. However, Cain ignores God, embraces his anger, and kills Abel. Ungodly anger impairs our judgement (Psalms 37:8) and leads to unhealthy conflict (Ecclesiastes 7:9).
God’s anger is directed at sin and injustice, and can be trusted. Our anger can be selfish and distorted by sin, so it cannot be trusted. Our anger can cripple our minds, so it can be hard to take on the mind of Christ. Anger is can be a poor motivator to action. It’s better to suspend our decision making until anger is no longer clouding our judgment.
Only when we master our anger can we search for the wrong which ignited it—starting with ourselves.