God was fired.
It's one explanation that makes sense. If I got the task of creating a world with happy beings living in harmony (I can't imagine anyone getting the purpose of the opposite) and I set up the first beings for a possible complete failure and they do, then I create a world where the beings have no choice but to kill other beings to survive, then they make war on each other and establish slavery and to save the situation I know no better than to send in my son and he gets killed and ever since one more horrific wars follows the next - and not only that - a big part of the beings start believing my place was created by someone else and half the beings die as kids - I'd be declared a failure and be fired. So that God has not shown himself the last 2000 years - it makes perfect sense that he got fired.