Revenge

Here you have the true reason why revenge or vengeance is not allowed to man: it is because vengeance can only work in the evil or disordered properties of fallen nature. But man, being himself a part of fallen nature and subject to its disordered properties, is not allowed to work with them, because it would be stirring up evil in himself, and that is his sin of wrath or revenge. God therefore reserves all vengeance to Himself, not because wrathful revenge is a temper or quality that can have any place in the holy Deity, but because the holy supernatural Deity, being free from all the properties of nature, whence partial love and hatred spring, and being in Himself nothing but an infinity of love, wisdom, and goodness, He alone knows how to overrule the disorders of nature, and so to repay evil with evil, that the highest good may be promoted by it. - William Law

All the ends of human happiness are secured without revenge, for without it we are permitted to restore ourselves; and therefore it is against natural reason to do an evil that no way co-operates the proper and perfective end of human nature. And he is a miserable person, whose good is the evil of his neighbor; and he that revenges in many cases does worse than he that did the injury; in all cases as bad. - Jeremy Taylor