Theists will often tell you that God needs the devil to tempt us in order to test us. I have always found this to be a very strange rationalization. It is a way of admitting that God is not omnipotent and is dependent upon Satan to fulfill his will.
@Lilac-Jade
And why did God order Abraham to offer up his only son as a human sacrifice and then change his mind in a cosmic "just kidding" exercise?
What's better than a good story but an eternal story, an archetypal story. Jordon Peterson explains these stories as enactments of dramas used to convey philosophical intuitions that had no language as yet. We have a lot of the language now and can express so much that we don't really need the dramas anymore. I hope, though, that we respectfully store these dramas so that future generations can always study the world we come from.
I'm hoping this will be the cap stone of the MCU or the DCU
Every politician knows that if you have prince charming kill the Boogeyman you had better have an Evil Troll hiding under the bridge, or else your own paladins might decide the real bad guy is you.