Hmmm.....
touchy subject for some....hope I don't piss anyone off here....
I think TCTC truly touches on this subject in the story of the Creator. When the creation of the rainbow somehow contains a flaw.
Thus we have the elixer of LIFE, the Yen and the Yang, positive & negative, dark & light, good & evil, and so on.

/
So the perameters are set.
There is a blight in beauty. There can be no light without darkness, you have NO point of reference to distiguish one from one another....,and the peoples now must choose.
It is the energy force we label as good/evil...as well as others named above, plus more....that gives the universe - whichever universe - it's motion into existance. The BIG BANG as it were.
At an atomic level, in the universe, even the protons, nuetrons, electrons, nuetrinos, protiens, amminos, etc. are attempting to align themselves with one another for a myriad of purposes. Such as creating planets, water, nebulas, suns, beings, and so on, including those things that blow-up and scatter the atoms, to once again regroup as.....something.
** The amazing thing in that point is that these elements can form together in an unlimited number of 'things'. Including 'things' who's existance we don't even know....yet. **
But on their journey to complete-ness, they must contend with expansion, dark matter, black holes, and other unseen-unknown energy forces that share space, and oppose. The Blight...?
But energy particles themselves have no sentient worries about there life cycle, that we know of. We do know that WE can neither create nor destroy energy, we can only affect it, change it, split it up or put particles together....but we have not figured out how to make or destroy it.
It is our sentience that creates the desparate need to choose quickly and often since our life spans are so short....comparitavely.
We create good & evil so that we can choose. It is not necessary, we
could live our lives without choosing any position on this good/evil issue.
But we have so little time to affect the future, for our posterity (haha, a microcosim of not being able to create or destroy even our own energies)....which is why I believe we choose to choose.
And then we make judgements on others for their positions, which begats another level to this thought process, namely what's Bad and what's GOOD. This helps to guide us to align with that which stands the best chance of thriving and surviving.
And there ya go, the rant of a crazy person.....or am I?
Destroy all that which is Evil, so that Good may flourish. -MacManus Bros.