When speaking about "God," the general population usually discusses views of Christianity. I would like to make a reference regarding a paragraph that Dan wrote in regards to why God would allow suffering to go on in the world.
Albeit, I really loved your analogy of a parent letting a child experience pain as way of rearing them to be better people...but I have to disagree with you, on that one.
Again...this is just my view, as a Christian. Since the beginning of the world, there has been a power struggle between God and Satan. This is referenced many times throughout the bible. God has always given man the gift of free will..starting in the Garden of Eden. When Adam and Eve were tempted by Satan and disobeyed God, he banished them from Eden. Over the books of the bible and the many centuries thereafter, you can clearly see the struggle between good and evil (God vs Satan). Those who are obedient to God are rewarded but those who give into Satan's temptations do not get the blessing hand of God over their lives.
In today's society where this is so much greed, hate, violence, sex, drugs, crimes, etc...it is our society's choice to give into those temptations...Satan's temptations. We all have a choice about what road we will choose...the one of righteousness or the one degradation. God hasn't left us (He's still here)...but rather we have left God.
I just wanted to share my take on what Dan had said:)