Be not angry that you cannot make others as you wish them to be, since you cannot make yourself as you wish to be. (Thomas à Kempis, 15th century German-Dutch cleric)
Anger is an insidious and often uncontrollable emotion. As Kempis suggests, when we are angry at the failings of others, we very well may be guilty of the same failures in ourselves. It’s easy to be critical of others and far more difficult to be honest about our own shortcomings. If we are upset with someone else, we would do well to examine ourselves first.
People with understanding control their anger (Proverbs 14:29).
Don’t sin by letting anger control you. Don’t let the sun go down while you are still angry (Ephesians 4:26).