Fast forward to the story of David and Goliath...Goliath was standing there shouting insults to Yahweh. It didn't offend Saul. It didn't offend David's brothers. They were ready for battle, however the king that should have been riding out in front was remaining in the camp. That is some king!
Who was it that was offended? David. The boy. He was so offended by Goliath's insult of God that he took matters into his own hands. He killed Goliath. Notice, the king was supposed to go out in front in battle. The true and eventual king did that day. David demonstrated what a king should have done.
David was the king that had his heart in line with God's. It was through his lineage that the ONE TRUE KING would arrive on earth. Just like David, Jesus led us into battle over sin. He went out ahead to the cross...suffered and died...then triumphed over Satan and sin so that we may live with him forever in heaven.