“Be ye angry, and sin not: let not the sun go down upon your wrath: Neither give place to the devil.” — Ephesians 4:26-27
There is a righteous anger, as well as an unrighteous. Else we would not read, “Be ye angry, and sin not.” If to be angry were already sin, we could not be exhorted not to sin in our anger. God is angry. He is angry with the wicked every day. His wrath is revealed from heaven against all that work iniquity. If it were not so, He would not be a moral being: for every moral being must burn with hot indignation against all wrong perceived as such. That is precisely what we mean by a moral being: a being which knows right and wrong, and which approves the right and reprobates the wrong. If we do not react against the wrong when we see it, in indignation and avenging wrath, we are either unmoral or immoral.
Therefore also, Christ was angry. The Gospels are filled with instances of the manifestation by Him of the emotion of anger in all the varieties of this emotion: from mere annoyance, as when He rebuked His disciples for forbidding the children to be brought unto Him, to burning indignation, as when the unfeeling Scribes would not permit Him to heal the suffering on the Sabbath day—yes, even to what the Evangelists do not scruple to call outbreaking rage which shook with its paroxysm His whole physical frame, as when He advanced to do battle with death and sin—the destroyers of men—at the grave of Lazarus. Even the Lamb feels and shows wrath. Christ is our perfect example. And if we are to be His perfect imitators, we not only may, but must, be angry; we not only may, but must, exhibit wrath—whenever, that is, good is assaulted and evil is exalted. We too, must be found, on proper occasion, with the whip of small cords in our hands; we too, must not draw back when righteousness is to be vindicated or when the oppressed are to be rescued. In this sense too, the wrath of man is to God for praise. We please Him when we are righteously angry. He who never feels stirring within him the emotion of just indignation is not like God in that high element of the image of God in which he was made—His moral nature. Indignation is an inevitable reaction of a moral being in the presence of wrongdoing, and it is not merely his right, but his duty to give it play when righteousness demands it.
No doubt we are to seek peace and ensue it. But this is the peace not of the condonation of evil, but of the conquest of it. We are to conquer evil in ourselves. We are to know no inordinate anger. We are to be slow to anger and quick to put it aside: we are not to let the sun go down upon our wrath. We are to remember that anger is a short madness, and not trust ourselves too readily in wreaking it on others—even when we think it righteous: not avenging ourselves, but giving place to the wrath of God, knowing that in His own good time and way He will avenge us. We are to conquer it in others: by the soft word which takes away anger, by the patient endurance which disarms it, by the unwearying kindness which dissolves it into repentance and love. Love is the great solvent; and love is the bond of peace. Where love is, there wrath will with difficulty live, and only that wrath which is after all outraged love can easily assert itself. But so long as there is wrongdoing in the world, so long will there be a place in the world for righteous indignation.
taken from: Warfield, B.B.. Faith and Life. 1916. Edinburgh: Banner of Truth, 1990. pp. 28-30