We must not destroy evil. We must fight... Robin Walz

We must not destroy evil. We must fight it, yes, every day and with every fiber of our bodies must we resent all that is evil. But we can never completely end evil, by no means. For what good is the light if there's no shadow?
If there's no more evil in this world, good men will cease to exist.
In fact, when being faced with this evil, it is the duty of every sentient being to rise above it and become better than the world that spawned it.