Righteous indignation is typically a reactive emotion of anger over perceived mistreatment, insult, or malice. It is akin to what is called the sense of injustice. In some Christian doctrines, righteous indignation is considered the only form of anger which is not sinful, e.g., when Jesus drove the money lenders out of the temple. (Gospel of Matthew 21)
Righteous means acting in accord with divine or moral law or free from guilt or sin. It may also refer to a morally right or justifiable decision or action or to an action which arises from an outraged sense of justice or morality. "Indignation" is anger aroused by something unjust, mean, or unworthy. The Standard Dictionary describes indignation as a "feeling involving anger mingled with contempt or disgust".[1]
Daniel Whitby argues that "Anger is not always sinful",[2] in that it is found among non-sinners. For example, Jesus was "angry with the Pharisees for the hardness of their hearts; yet He had no desire to revenge this sin upon them, but had a great compassion for them". In Scott's comment on Ephesians 4:26, he notes that "...on many occasions, in the management of families, in reproving sin, and even in ordering their temporal concerns", anger is permitted of Christians. Nevertheless, Scott cautions that Christians should aim to "....be very circumspect and vigilant to restrain that dangerous passion within the bounds of reason, meekness, piety, and charity; not being angry without cause, or above cause, or in a proud, selfish, and peevish manner." In contrast with some commentators who argue that righteous indignation may be a permissible form of anger within the Christian religion, Scott argues that Christians should not express anger in the "language of vehement indignation".[1]
The Forerunner Commentary on Psalms 137:2 argues that these psalms are about the "bitterness of exile into which God forced Judah", purportedly with the goal of turning grief into zeal, so that the "anger can be used to scour away sin" by becoming "righteously indignant".[3] In Richard T. Ritenbaugh's comments on Proverbs 15:18 in How to Survive Exile, he argues that it "is alright for us to be righteously indignant as long as we do not sin."[3] In McCosh's book Motive Powers, he notes that "We may be angry and sin not; but this disposition may become sinful, and this in the highest degree. It is so when it is excessive, when it is rage, and makes us lose control of ourselves. It is so, and may become a vice, when it leads us to wish evil to those who have offended us. It is resentment when it prompts us to meet and repay evil by evil. It is vengeance when it impels us to crush those who have injured us. It is vindictiveness when it is seeking out ingeniously and laboriously means and instruments to give pain to those who have thwarted us. Already sin has entered."[1]