Ephesians 4:26

Be ye angry, and sin not: let not the sun go down upon your wrath.

This verse can be misread, as if it said, "Be sure to be angry now and then, but do not sin." It appears that the meaning is, "When you are angry, be sure that you commit no sin." Anger is a time when sin strongly presents itself as a temptation to violence or other retaliatory action directed against the object of one's anger.

Anger is even attributed to God Himself; therefore the teaching cannot mean that it is a sin to be angry. There are things which certainly should arouse the emotion of anger in Christian hearts. About the most ineffective person on earth would be one incapable of being angry.

Let not the sun go down ... Even when anger comes, it must be terminated quickly. Sundown is the time for removing anger from the heart. When anger remains, it can corrupt and destroy every virtue of the soul.