Really?

I am a big fan of Sunday school. I love Addison's excitement on Sunday morning to go to church and then listen to her tell us about what she has learned on the way home. I really believe it is vital to teach my children Bible stories at a young age and to teach them about God's love. However, as good as Bible stories can be, I don't think all stories should be told. Just when I am trying to teach Addison NOT to throw rocks, push her friends she comes home with quit the story. This month's lesson is David and Goliath. Yes, I understand it has been in children's Sunday school curriculum even before there was Sunday school. Every child can recite how David was a hero when he trusted God to take care of him and defeat mean-old Goliath.
I have one question: how did this become a child's story? While I understand the context of the situation...David was fighting the enemies of Israel, God's chosen people. This was vital to the well being and advancement of the people of God. Now how does one explain that to a two year old? We don't. We just tell the miraculous part: David killed the giant.
So now, Addison, yes people are mean. And since they are mean, you can throw rocks at them and with God's help, you can cause them to fall down and never wake up again.
Perhaps it would be better to stick with Jesus feeding the five thousand.