Epicurus' old questions are yet unanswered.
Is God willing to prevent evil, but not able? Then he is impotent. Is he able, but not willing? Then he is malevolent. Is he both able and willing? Whence then is evil?
God 'letting' us commit evil through an ambiguous idea of free-will still does not answer the question of why evil exists in the first place. The question is still not answered if one says that that evil exists because of human sin. Epicurus' questions are still valid.
Free-will really has nothing to do with it. If god is omnipotent and created everything, then it logically follows that god created evil. This is incompatible with his supposed omnibenevolence. Besides, sin is subjective and finding out what is good is not helped by invoking what a deity supposedly said. This god could just as easily say that murder is good as say it is bad. But would murder be any more abhorrent?
You see the thing is that if you say that human evil is somehow different and apart from other terrible things that happen around the world (e.g. earthquakes, disease, suffering animals, etc) I would like to know how you make the distinction. Where, if it exists, is the line that distinguishes a solely human evil, one that no other life form on the earth can experience, from an instance of evil elsewhere in the world?
Seeing as you may agree with the traditional Christian approach to the advent of evil, how does one explain the existence of 'evil' before it's advent? According to conservative estimates, 99.5% of every species that has ever existed on earth has become extinct. Indeed, homo sapiens were lucky not to have fallen over the brink themselves. Long before Adam or Eve ever arrived, animals and life had been neck-deep in the struggle for existence that in all likelihood included every 'evil' we know today occurring on a regular basis.
What if someone were to say that even though god created evil, or at least can never remove it, it is up to us to 'rid ourselves'? There is so much wrong with that it boggles the brain. "Created sick and commanded to be well" comes to mind. The deeper question though would still stem from Epicurus, namely, what is it about this 'evil' that God cannot remove? The free will defence is unsound and the only thing we have to go by is experience which tells us that both evil and good are human constructs. The hawk thinks nothing of killing the mouse but the imminent feeding of it's hungry belly.
So what if the 'evil' is going to be overcome in another world! This answer does nothing to explain the persistence of pain and suffering in the only world we know to exist. I could posit any number of next-worlds or previous-worlds in which certain aspects of the universe were 'overcome', but it would do nothing to explain why those attributes exist in the here and now. It's a nice side-step of the problem of evil but it won't do.
As I see it, the dormitory is that way simply because it functions that way. If it were different, then it would be different and we would still squabble over the particularities of that difference. Apart from ambiguous texts written by ignorant, scared, credulous humans we have no indication that the world has ever been different. Some perfect world is only a fantasy, either in the past or in the future.