“Let every person be quick to hear, slow to speak and slow to anger, for the anger of man does not produce the righteousness of God.” (James 1:19-20)
Incredibly, Christ’s commentary on the sixth commandment includes a person’s inner state. Anger is subject to God’s judgment (Matthew 5:22). This was not original with Jesus. Moses had already recorded God’s will, “You shall not hate your brother in your heart . . . or bear any grudge against the sons of your own people, but you shall love your neighbor as yourself ” (Leviticus 19:17-18). Lack of love, as well as positive hatred, is a form of murder.
Anger is not always wrong. If it were, God would be the chief sinner, for he is angry every day (Psalm 7:11). And note that David does not say God is angry merely at sin. He is angry with wicked people. The wrath of God is seen throughout the Old and New Testaments and is the inevitable result of his holy character exposed to unholy attitudes and behavior.
But is it possible for a sinful mortal to be godlike in his anger? It must not be easy, for the Bible is filled with teaching against anger. Anger is to be put away (Ephesians 4:31; Colossians 3:8); whoever is angry is in danger of judgment (Matthew 5:22); anger is one of the works of the flesh (Galatians 5:19-20); it does not work the righteousness of God (James 1:20); and it is the prerogative of God, not man (Romans 12:19). Proverbs condemns anger repeatedly.
But Jesus was angry (Mark 3:5), and we are commanded in our anger to refrain from sin (Psalm 4:4; Ephesians 4:26), to be slow about it (Titus 1:7; James 1:19), and to get over it quickly (Ephesians 4:26). There seems to be approval of being angry under some circumstances, but the major biblical emphasis is on anger as evil; exceptions seem very limited.
Anger at sin, even anger at the sinner, can be a good thing (1 Corinthians 7:11). Jeremiah was full of the fury of the Lord (6:11), and Paul was angry over the idolatry of the Athenians (Acts 17:16). Yet Christ himself refrained from anger when the offense was against him personally (1 Peter 2:23-24), and “like a sheep that before its shearers is dumb, so he opened not his mouth” (Isaiah 53:7).
Righteous and unrighteous anger can be distinguished by the cause of anger. One should be angry over sin that offends God, harms others, or harms the person sinning. The difficulty with being righteously indignant is that our motives are mixed. Am I distressed over a sin that offends God and harms people, or am I angry over the way I am affected? Since motives are mixed, the safe thing may be to eschew anger altogether when the sin of another directly affects me, as when my child does wrong but the wrong embarrasses me. Better to wait till the anger subsides to be sure the resulting action does not come from a mixture of righteous and unrighteous indignation. Anger is sinful when it is for the wrong reason or results in the wrong action.
To keep this emotion from igniting for the wrong reason or from burning out of control, Scripture gives two ways of control: Take it easy — don’t get angry suddenly (James 1:19), and don’t let it keep burning — don’t let it last till the next day (Ephesians 4:26). Either a “low flashpoint,” a quick response without reflection, or a “slow burn,” continuing on with the emotion, seem to risk causing even righteous indignation to go astray.
Against the clear teaching of Scripture that most (not all) human anger is wrong, and that the proper response is to control it (Proverbs 16:32), many Christian psychologists hold that anger is morally neutral and must be expressed. To this we respond that anger is neutral in the same way that hatred and killing are neutral: Sometimes they are right; mostly they are wrong. Anger in itself is a wrong emotion to have if it is directed against the wrong object (God, an innocent person, a thing); for the wrong cause (personal offense); or leads to wrong behavior (retaliation, vengeance, physical violence).
Anger under these circumstances should not be denied or expressed. It should rather be confessed as sin and the resources of God appropriated to control the emotion itself. We need to be encouraged to evaluate in the light of Scripture whether our anger is godly and, if it is not, to confess our sin, thus removing all guilt. Then we should trust God for his resources in overcoming the temptation.
How is this for you? Perhaps you excuse anger as justified. Are you offended? Is the object of your anger appropriate? Can you maintain self-control? Do you want your own way? Are you protecting yourself or others? What is the outcome of your anger? Take a few minutes and reflect on the impact of your anger and how you might have a reason, action, or outcome that honors God.
 Simon Kemp, K.T. Strongman, “Anger theory and management: A historical analysis,” The American Journal of Psychology, Vol. 108, No. 3. (Autumn, 1995),397–417.