While a great many godly people think that the destruction or elimination of the ungodly is the best way to establish goodness and godliness on earth, that does not seem to have been God’s plan as revealed in His Son. “For God so loved the world that He gave His only begotten Son, that whoever believes in Him should not perish but have everlasting life” (John 3:16). In fact after the great flood reported in Genesis, “the LORD said in His heart, ‘I will never again curse the ground for man’s sake, although the imagination of man’s heart is evil from his youth; nor will I again destroy every living thing as I have done'” (Genesis 8:21). God repeats in Genesis 9 His promise to never again destroy all humanity because of sin, and puts the rainbow in the sky as a sign and reminder of that promise.*
It ends up in God’s plan that a good man dies for the life of the world. The death of an evil man, or even of many evil men, or if it was possible of all evil men would not have saved the world. The death of humans cannot bring an end to evil in the world, though admittedly it will stop the one who dies from committing further evil (or further good for that matter). “As surely as I live, declares the Sovereign LORD, I take no pleasure in the death of the wicked, but rather that they turn from their ways and live. Turn! Turn from your evil ways! Why will you die, O house of Israel?” (Ezekiel 33:11).
Christians have not always valued that self-emptying love, the self-sacrificing love, or the co-suffering love which Christ modeled for His disciples to follow. We usually want it to be the death of the other person – the bad person – which will save us. Jesus said, “Whoever desires to come after Me, let him deny himself, and take up his cross, and follow Me. For whoever desires to save his life will lose it, but whoever loses his life for My sake and the gospel’s will save it” (Mark 8:34-35).
To follow in Christ’s love, to imitate Christ, is not to kill the sinner but to change the sinner. “He who turns a sinner from the error of his way will save a soul from death and cover a multitude of sins” (James 5:20). Our task is not to kill the sinner, but to turn the sinner away from death.
*Despite God’s conclusion that evil cannot be killed, the Byzantine Emperor Justinian in the 6th Century believed his army could defeat Satan. If that seems laughable, one only needs to think in modern times that Osama bin Laden is also leading a war against evil which he believes his legions can win. Let us not forget our own President Bush taking the U.S. military into war to destroy what he labeled as evil. Human thinking does not change easily. We want to kill evil, and certainly favor killing the other over imitating Christ and sacrificing ourselves as the way to defeat evil. Some might say in defense of war/killing, didn’t Jesus teach, “Greater love has no one than this, that he lay down his life for his friends”? (John 15:13) The answer is YES. But then note, he said to lay down one’s life, He didn’t command taking up arms. In other words, we can die for our friends like He did. He didn’t command killing for our friends. “Love one another,” Jesus said.
Fraternized 
Why can’t God destroy the rebellious angel, so it would not tempt people and create evil within us? Since God promised not to destroy the earth and its people, can He still destroy the disobedient angels, thus the root of all evil will be gone and it would not be able to tempt people anymore?
Jules,
Good question. I cannot say I always understand the logic of God or what is possible and not. It does appear to me that God for whatever reason chooses not to annihilate disobedient angels. Perhaps this cannot root out evil from our world anymore than drowning humanity in the flood could. God seems intent on working out His plan and purposes within the universe He created. Perhaps any effort to destroy evil must by necessity also destroy good as well. God works with the good and seems to accept that evil is part of the created world – even in Paradise after all the serpent was present. The usual sense of why this is the case rests in a notion that for love to exist there must be the ability to freely choose love, and if free choice exists it means there must be an ability to choose evil. To annihilate evil would also result in the destruction of love and free will, something God is apparently not willing to tinker with, no matter how much we like the idea. There apparently is something so valuable in love and free will in God’s eyes that He accepts that evil must be a possibility for love and free choice to exist.