The world can never be perfectly good or bad. Good and bad are two inseparable things. One can't be ended without ending the other. The only way to stop evil is to stop good also. Happiness without misery is a contradiction. There is nothing in this world that can be labelled as purely good or purely bad. Moreover, good and bad are relatives terms. The same thing which is appearing good now, may appear bad tomorow. The same thing which is producing misery in one, may produce happiness in another.