I fully agree there are a million lessons about David and Goliath that need to be taught and our kids need to consider. It’s a wonderful story to act out and tell. But in God’s eyes David was proven worthy of the kingship because of his handling of Saul, not Goliath. After the Goliath incident God may as well have had a Samson on his hands. It was as David trusted God and let himself be trapped by his respect for Saul, and his trust in God, that David became worthy of the Kingship. Our great calling includes slaying giants, and we have many to deal with yet. But we won’t sit on God’s throne with Christ unless we figure out what David wrote in his many Psalms, about how to survive those we love, those we trust betraying us, and our commitment to the Lord to deal with their sin against us. It’s his house after all. He is the head. If we try to cut off the head God intends to cut off himself we may end up fighting God.