In the generation before Shakespeare, the French essayist Montaigne remarked that cruelty and vengeance are so inherent in human nature that we wouldn't be ourselves without them. In so many words, Shakespeare said the same thing in his tragedies and histories. Would Hamlet be as interesting if he weren't bent on revenge, or Lady Macbeth without her blood lust? This is a serious question for anyone who wants human nature to transcend its base impulses. I think that what makes Buddha and Jesus so radical is that they gave up on hand-wringing, moralizing, and wishful thinking. Instead of healing human nature, they proposed radical surgery to completely alter it. Aiming at a spiritual revolution that far exceeds spiritual reform, they had to connect pain with a more profound problem: evil.
If pain isn't a sufficient deterrent to the evils of human behavior, what is? An obvious answer is morality and religion. Officially, the entire network of moral teaching that envelops every culture is meant to extract our better impulses from our worse ones. The theory is that you sort out your angels from your demons and follow the angels. To back up morality, the law punishes anyone who seriously transgresses the boundary between right and wrong. But one could easily argue that the very people who obey the law and follow the dictates of morality are cut out to be that way already. They don't feel overly tempted by violence, vengeance, sexual hunger, and misanthropy to begin with. (Just as naturally thin people wonder why dieting is hard. For them, it isn't.)
Religion has always had divine punishment lurking behind the altar or in the cellars of the Inquisition. As a preventive to war and sin, the results have been dubious, to be kind about it. The moment one faith challenges another, a brutal infliction of pain seems to be the inevitable outcome. One is hard pressed to think of any war settled by a church on behalf of a higher wisdom, and this includes the war within human nature.
Jesus and Buddha were astute enough to see this problem; therefore they didn't offer sermons and palliatives. They observed human nature at war between pleasure and pain, a war that is eternal as long as one remains on the field of combat. In essence Montaigne was right: human nature as we experience it must be divided if we are to consider it human. However, spirituality says that human beings have both a psychology and a meta-psychology. It is in our nature to transcend our nature. What makes us unique as a species isn't a capacity for good and evil, or being conscious of good and evil, not even a willingness to conquer evil in the name of good. None of those qualities has solved the dilemma of being at war inside ourselves.
The only answer is to give up being a person, as that condition is normally defined. One Indian guru said, "As long as you have a personal stake in the world, you will never be free." What does this mean? Ultimately what drives us, at the very deepest level, is not a fantasy of everlasting happiness but the actuality of freedom. The peace that passes understanding says to Christians what Satori says to Buddhists: this is the real you. Evil's fatal flaw is that it feels false; it strangles and suffocates who we really are. The seductiveness of evil is undeniable. Why else would we be locked into suffering? Freedom doesn't need to seduce, any more than love does. It's the very seed of existence. Insofar as any person pursues freedom, he or she pursues the truth of existence.
If that is the core message of Buddhism and Christianity (not to exclude any other faith that brings the same message), then good is sovereign over evil in the grand design. A lofty sentiment? Yes, but by setting foot on the spiritual path, the sentiment turns into reality. Hamlet was wrong when he asked, To be or not to be? There's no alternative to being; we only have to decide the quality of being, whether to be trapped or free. The most interesting life anyone can lead is a life of self-exploration, not in the interest of pleasing God or gaining knowledge, but to discover once and for all if absolute freedom is attainable. The practical result is an end once and for all to our everlasting addiction to pain.