In matter-ism (materialism), there can be nothing wrong with the world since there is no right way for the world to be in the first place. Everything is just matter in motion and that's that. In Mind-ism (monism) there's a different route to the same problem. There cannot be a problem of evil, even in principle, since in Mind-ism even morality is maya; illusion. In neither story, then (if we're to be consistent with their principles), can the issue of evil be raised. But in real life the problem comes up all the time. That's the difficulty.