I think you may have hit it on the head already, but in fact evil is not a thing. It is a misuse of something inherently good. And God did not create evil, it was a byproduct of the fact that he gave free will to men and angels. Lucifer chose himself over God, making himself his own god, thats the nature of the fall, and what some theologians call the primary sin, that of hubris. But ‘evil’ as a notion was not created, and the definition for it is merely the absence of God. It would be like calling dark a thing. We only know that light is a thing with a tangible source. Darkness is merely the absence of light. If we didn’t know light, we would have no concept of darkness. But without darkness we would still have a concept of light because of the tangibility of a light source. The same applies to evil and good. Goodness can be inherent, and good actions can be done simply for the sake of doing good, but evil cannot be done for evils own sake. And all of this falls under the fact that we were created with the free will to choose. If God created us without the free will to choose good over evil, we would all be dragged kicking and screaming into heaven, and that isn’t love at all.