From Karis elder Aarik Danielsen's message from Sunday out of Exodus 17:8-16: 

But God is determined to win for himself a people and so he provided deliverance through someone far more powerful than Moses. Moses is a hero of the faith, but he is not the real hero of the story. God gives us Christ crucified to bring about the most decisive deliverance the world could ever know. In every way Christ is the better Moses. Moses was faithful; Jesus is the author and finisher of our faith. Moses communed closely with God; Jesus has existed in community with the Father since before time began. Moses’ strength failed him and his arms fell to his side during the battle. Jesus endured more excruciating torture than Moses could have imagined, yet his arms remained outstretched on the cross until the job was done.