The world has to modes: In one mode, we need people, as much as we can get, to make something bigger out of this world. In another mode, the world can no longer grow, so we divide, we conquer "the others" or be conquered.

The definition of the word "evil" changes depends on which mode we are in.

That's why Niccolò Machiavelli suggested that it is useful to be both loved and feared, it gives you the best chance when a challenge is facing you.