Anytime you start linking "anger" and "sin," Christians generally pull out the trump card of Ephesians 4:26 - "Be angry and do not sin; do not let the sun go down on your anger..." The argument is fairly simple: This verse separates anger and sin; therefore, it is possible to be angry and not be sinning; therefore, anger (in and of itself) is not a sin.
Following this line of reasoning, I used to believe that anger itself was not sinful, that rather, it was what you *did* with the anger that mattered. I no longer believe it's that simple. I've come to see how the emotion itself, not just the actions that accompany it, carries potential for sin and needs closer examination.
Anger is a response to a perceived wrong. We get angry when something is not as we think it should be. And so anger is not automatically valid, a neutral emotion to be expressed, "vented," voiced and affirmed. Whether anger is right or wrong depends first on whether our perception of reality is right or wrong.
Dr. David Powlison writes:
"The arousal of anger is either good or bad. It may arise for good reasons: e.g., someone I trusted betrayed trust, or someone threatens to harm a child. It may arise for bad reasons: e.g., I'm stuck in a traffic jam, or someone at work had the audacity to disagree with my brilliant ideas and plans.So the potential for sin isn’t simply in how anger is expressed. There’s also sin potential in my anger itself—is it justified, or is it rooted in attitudes and expectations that exalt me and ignore the true and living God? I’d argue that most of the time, at least in my life, it’s the latter. My anger may be “understandable” to fellow sinners—but it’s not righteous in God’s sight.
The motives for anger are either good or bad. Desires, beliefs, expectations, values, intentions may be good. Jesus' anger expresses faith working through love; our anger can move in his direction. Or our motives may be bad: wrong beliefs, idolatrous desires, self-pity/self-righteousness.
And, of course...the expression of anger is always either good or bad (or, again, that complication in things human, mixed). For example, anger expresses love when it energizes you to protect the helpless by opposing victimizers. And anger expresses hate when you get into petty arguments or when you bully others.
That doesn't mean I think anger should be stuffed and ignored. I think it should be acknowledged (just check out the Psalms), worked through, and repented of if necessary. But I don't think it should be unchallenged.
Dr. Powlison elaborates in chapter 13 of his book Seeing with New Eyes: Counseling Through the Lens of Scripture:
“Anger, like all emotions, is something you do as a whole person. Anger involves active things such as thoughts, attitudes, expectations, words, and deeds, as well as the more passively sensed ‘feeling’ of being angry. …Anger is a common human response to a perceived wrong. It is even part of being made in the image of a moral God. Anger can be either right or wrong. …Biblically, anger may be either justified or unjustified, either wrongly or rightly expressed. It is much more than an emotion. Human anger is potentially righteous but is usually laced with sin.I hope that helps to clarify my thinking on the issue of anger. In summary: Anger isn't always wrong, but it often reveals the idolatrous desires lurking in the human heart. And if my anger is prompted and driven by idolatrous demands, then it's sinful, regardless of whether I outwardly treat people wrongly in my anger or not.
“The need for an objective, moral evaluation is obscured when anger is viewed simply as a feeling. If anger is a feeling that happens to me, then it is intrinsically legitimate. ‘Just as when I cut my finger I feel hurt, so when you offend me I feel angry. I need only to get in touch with my anger and then express it in socially appropriate ways.’ But when anger is evaluated by God (e.g., James 1:19-20; 3:2-4:12) that simple equation breaks down. I acknowledge anger in order to examine it in God’s light. In all likelihood I will learn about my self-righteousness, my god playing, my demands. I will be brought to my need for God’s grace in Jesus Christ” (p. 212-213).
Feel free to ask more questions if I haven't been clear here.