The mediation by the serpent was necessary. Evil can seduce man, but cannot become man.

Work is a necessary evil to be avoided.

Politics is a necessary evil, or a necessary annoyance, a necessary conundrum.

Evil is whatever distracts.

The world is the best of all possible worlds, and everything in it is a necessary evil.

Government, even in its best state, is but a necessary evil; in its worst state, an intolerable one.