Have wrath, just don’t do evil: this seems to be the Biblical idea about how to deal with people if some tougher mode is required: if it is required, use the tougher mode (have wrath). There is no meaning in whimsy-flimsy behavior if only strength and tough, honest words lead to the goal. This phrase is actually something Paul wrote once to the Ephesisans: “Be angry, yet do not sin” (Eph. 4:26 ISV); so, it is “biblical”. (On a side note, this is not necessarily a quote from Ps.4:4 which rather speaks against wrath at all; because this connection can only be made via the LXX version, says Matthew Henry in his commentary on Eph.4:26.)
But then also, as Paul goes on to say: “Do not let the sun go down on your wrath!” (Eph.4:26 ISV) . What does he mean? Know the limits of your wrath. When keeping wrath long term (“over night”, and longer), it breeds aggression and every kind of evil-doing. Therefore it is necessary to limit it to being a short-term emotion. Because then it is just a mode of more powerful social interaction: using the human expression abilities to full potential where that becomes necessary. It seems to me that Paul means this function of wrath here.
Remaining things to think about here:
- What role does culture have here? Is it wise to adapt the severity of ones expression of wrath to the surrounding culture (like being less wrathful in Asian countries, as they are not used to it, but being more wrathful in South European countries, as they get the message only then?)
- How to “not let the sun go down” if the reason for ones wrath is still there on the evening? Wouldn’t it corrupt ones message and credibility to still reconcile with the other party?
- What actually are legitimate expressions of wrath if doing evil (like destroying things, shellacking people) is not included? From the example of Jesus it seems that screaming and shouting is not even necessarily a part of showing wrath, rather a sharp message that is uttered in a direct, authentic, but sober-minded, low-emotional way.