I told my 7 year old niece that we are made of the same stuff as the stars in the sky and the icky pollution in the river. That we are here to get better, and that some people believe better to mean being nice and kind, not getting mad, and to learn from our mistakes. I told her that some people think better means getting more than everyone else, being greedy, wanting to be number 1 at any price, stepping on people to get what they want, being greedy and bad. I asked her if that made sense and she said "sort of." So I told her to just try to be good and not to do anything to anyone that she wouldn't want to have happen to her, and that made made her happy.