@fresco Let me first state that I'm not religious and am not any of the major religions. I'm giving my opinion on, if there is a deity, why there is so much "injustice" in the world.
I don't have answers to a lesson learned by that child. I can only rationalize that, if there is a god, the child must be serving a purpose. For example, in christianity, jesus died for humans sins. What happened to him in the bible was definitely unjust, but god let it happen right? And there was an underlying reason. In the same sense, a child on earth may be only a physical form of a deity sent to teach a lesson to someone else. Or IF souls do exist, and "free will" is a creation of god, maybe the soul made the choice to go through that life to teach a lesson. Maybe they're all angels. Who knows. I have no answers to that and no one does. I can only offer an alternative viewpoint.
I'm under the impression you don't believe in some for of deity. If that's the case, I'm probably not going to sway you either way and you'll likely be closed off from these views.
In terms of "evil", its what society views as evil and that exists on a spectrum. For example, is it evil to test animals for the benefit of humans? By your definition, yes. Does that stop you from using things that are derivatives of these exploits? probably not. Using your rationality, can I then classify you as an "evil" person? yes. Kind of like that moral complex where you kill someone you know to save many people or you save one person and kill many.
Not sure whether you're being sarcastic or not. but thanks for the history lesson.