Question: "What does it mean to not let the sun go down on your anger?"
Answer: Ephesians 4:26–27 says, “Be angry and do not sin; do not let the sun go down on your anger, and give no opportunity to the devil” (ESV).
Paul gets practical in the latter half of the letter to the Ephesians. In this section, he exhorts believers to tell the truth to each other, be angry without sinning, stop stealing, work so they can give to others in need, use their words to edify others, not grieve the Holy Spirit, put away sins such as anger, be kind to others, and forgive others just as God has forgiven them.
In Ephesians 4:26, we have the command to “be angry, and yet do not sin” (ESV). This statement is probably a reference to Psalm 4:4, “Tremble and do not sin.” This particular psalm is sometimes titled “A Night Prayer” or “An Evening Prayer of Trust in God.” Verse 4 continues, “When you are on your beds, search your hearts and be silent.” Perhaps this part of the psalm was meant to help the prayerful reader resolve any anger issues in the heart before going to bed. Paul uses this Old Testament passage as a springboard for his command to “not let the sun go down on your anger.”
Anger itself is not sin, but how we use it determines whether it is sinful or not. Legitimate righteous anger toward sin or injustice can be productive. Jesus exhibited righteous anger at times, most notably when He cleaned out His Father’s house, the temple (John 2:13–16). But, more often than not, anger becomes sinful because our own selfish interests and pride motivate it. Someone or something offends us, and we lash out. We end up saying and doing things that we ought not. Anger rooted in our own sinfulness is dangerous and destructive to others and to ourselves.
One thing that can turn anger into a sinful attitude is to allow it to continue to fester instead of acting on it in a righteous manner. Our exhortation is to not let the sun go down on our anger or, as the NIV has it, “Do not let the sun go down while you are still angry.” To allow a period of anger to be unreasonably prolonged is to “give the devil a foothold” (Ephesians 4:27).
The Bible has many warnings against the improper use of anger. In the same chapter as we are told not to let the sun go down on our anger, we have a command to put away anger (Ephesians 4:31). James commands us to be “quick to listen, slow to speak and slow to become angry” (James 1:19). David writes, “Refrain from anger and turn from wrath; do not fret—it leads only to evil” (Psalm 37:8). Solomon adds his wisdom: “Do not be quickly provoked in your spirit, for anger resides in the lap of fools” (Ecclesiastes 7:9). The book of Proverbs echoes the cautions about anger: “Whoever is patient has great understanding, but one who is quick-tempered displays folly” (Proverbs 14:29), and “Good sense makes one slow to anger, and it is his glory to overlook an offense” (Proverbs 19:11, ESV).
Anger must be controlled, and we should never use it to sin. If we do become angry, we should deal with the anger and its root quickly and then promptly put it away from our lives. We should strive to “keep short accounts” and forgive those we need to forgive in a timely manner—before the sun goes down. If we hold on to anger, we run the risk of bitterness and resentfulness, which provide the devil with a foothold in our lives. Unchecked anger among believers will break fellowship and bring damage to the church. We must be careful to heed the closing exhortation of Ephesians 4, “Be kind and compassionate to one another, forgiving each other, just as in Christ God forgave you” (Ephesians 4:32).