"Be ye angry, and sin not: let not the sun go down upon your wrath" (Ephesians 4:26).
In our text, the verse instructs us to be angry and yet not sin. But the Bible clearly condemns losing one's temper. Indeed, just a few verses after our text we find: "Let all bitterness, and wrath, and anger, and clamor, and evil speaking, be put away from you, with all malice" (v.31). So when is it appropriate and when is it a sin to be angry? The life of Moses provides the answer.
After God's powerful demonstrations in bringing plagues upon the land of Egypt, Moses declared God's final judgment on stubborn Pharaoh. Exodus 11:8 records that Moses "went out from Pharaoh in a great anger." There is no divine condemnation for this just anger at the hard-hearted monarch. Also, when the children of Israel left Egypt they sinned against God by fashioning an idol. As Moses "came nigh unto the camp, that he saw the calf, and the dancing: and Moses' anger waxed hot" (32:19). Here Moses became legitimately angry at gross sin against God.
But there is a third scenario that is recorded for us in Numbers 20. Moses was frustrated with the thirsty and murmuring Israelites. God commanded him to speak to a rock to obtain water from it. "And Moses . . . said unto them, Hear now, ye rebels; must we fetch you water out of this rock? And Moses lifted up his hand, and with his rod he smote the rock twice" (vv. 10-11). God immediately reproved Moses for his angry disobedience. So we note that it is appropriate to be angry at hard-hearted disobedience and to express self-controlled outrage at sin. But anger is never justified solely because of frustrating circumstances and especially if it results in personal disobedience. "For the wrath of man worketh not the righteousness of God" (James 1:20). DW