The so-called Problem of Evil---the greatest intellectual labor-saving device to date among lifelong ignoramuses---may be the most obviously fallacious argument in human history.
It's so important to consoling one's permanent shallowness that it's become a global monomania in the God debate that fixates the masses of glib deadbeats on all sides of the God question. A couple of new edits inserted, based on a remark by William Sahakian in describing Schopenhauer's view of evil.
This definitional dependency embarrasses the mere concept of the problem of evil.
You don't add anything to dislike by calling it evil. Just as Schopenhauer said about pantheism: you don't add anything to the world by calling it God.
To recognize anything to be evil or negative in any sense beyond human dislike or loathing already requires a problem-free ultimate ideal goodness to contrast itself to and therefore give it meaning and recognizability as evil instead of being merely disliked, however extreme, exceptionless, and absolute that dislike might be on its own. This is how the problem of evil steals its meaning.
Evil can be recognized as evil only in the light of a contrasting already-existing problem-free good.
Without some concept of perfect goodness, you don't get to add the histrionic "evil" label to "everyone dislikes it" and get out of that anything more than "everyone dislikes it".
So the whole problem of evil is on definitional welfare.
It's something you do when you need evil so much that you're willing to steal its criterion of meaning from the concept of ultimate perfect goodness to even know that it's evil in the first place.
This is why the problem of evil is a childishly stupid objection.