Revenge is theological. To be abased or abused by another causes one to see one has lost value in the eyes of that other. But who is that other? Why does he or she have authority? If the other is the other and no more than that there is no especial reason to elevate the other’s opinion of oneself to a higher status than one’s own opinion of oneself. Suppose I think myself a worthy fellow. Then someone treats me as if I am unworthy. Why should I believe him rather than myself? But it happens that we do tend to respect the other’s opinion not simply as a judgment on us, whether an accurate judgement or not; the other’s abuse of us is not simply an expression of a judgement. The abuse is experienced as a making of that judgement the truth. To pronounce guilty, in this sense, is to make the object of that pronouncement guilty. This is no case of “guilty as charged,” but “charged, therefore guilty.” Just as God’s “fiat lux” does not express a wish for light or the expression of a truth that light would be a good thing, but does in fact cause the existence of light, so the abuse we receive makes us deserving of it. This perception or feeling, however irrational, is the experience of abuse (leading to desire for revenge) no matter how truly we may argue the abuse was undeserved and does not pay due respect to our true self.
The abuser, therefore, is treated as being the manifestation of God’s power and authority.
God, therefore, has proclaimed us into unworthiness via his messenger. What are we to do? We cannot “prove” our innocence as one might do in a trial, or in the appeal of a faulty verdict. Or rather, on a rational and evidential basis we might indeed prove our innocence, but such proof is rendered null and void by the idolatry that treats the abuser as a manifestation of God.
Therefore, we must abuse, even kill the messenger. If we can do this, we can show to ourselves that he or she was not God’s messenger to begin with. If his power to hurt us indicates God’s authority, our power to hurt this messenger negates him as God’s messenger. The authority of the abuse against us is vitiated. To get revenge is to say to the abuser “no, you are not the voice and power of God.”
But perhaps, at the darkest level, to get revenge is to unseat the offender from being the voice and power of God, as if the offender really had been that. Note that this is not a case of proving the abuser to be a false prophet. Prophets are not killed because they are false but because they are true (or seen as such). Likewise, the abuser is believed (at some deep level at least) to be the true power and authority of God. However, the avenger aspires to change this state by the injury or destruction of said abuser.
Convicted by The Truth (regardless of the fact this “truth” may be a blatant falsehood) one therefor assaults The Truth, assaults God through assaulting his “prophet.” One therefore treats God like a puppet who can be forced; this action is tragic.
Perhaps, therefore, when God says, “revenge is mine” he may well be not only delineating the difference between human and divine responsibilities but saying that he shall not be our puppet.
Revenge, therefore, is unfaithful and idolatrous. But it also reflects a belief in God, a passionate need not to be rejected by him. Perhaps it is the case, therefore, that those who can be greatly provoked without experiencing the desire for revenge are either people of great faith (whether or not it is linked to a specific religion or set of doctrines) or very thoroughgoing atheists. Revenge, in effect, is for believers who lack faith.
So, revenge is not a matter of “tit for tat” as it is usually conceived: a spiritual or moral Newtonian motion where an action demands an opposite and equal reaction. If you hurt me and I therefore want to hurt you, that is not the same as the firing of a gun causing recoil.
Revenge is not a matter of justice, not even retributive justice, but an attempt at the justification of the self. This justification is attempted through an assault on God, the source of all justification.
Indeed, if there is any truth to what I have said here, it might illustrate in some way the Christian belief that we cannot justify ourselves. Only God can do that for us. “Revenge is mine,” he says in Romans and Deuteronomy.
Revenge is inspired when one first commits the idolatry of taking another person’s judgement of oneself as coming from God, and ends up assaulting God himself to achieve the justification ruined by this very idolatry.