The word "bapto" is where we get our "baptise" and it means to color something, cover its surface completely in dye (by immersion). To be covered by the blood of Jesus means to be baptized in it. Blood is the life of the flesh - Leviticus 17:14, so we should cover ourselves with the life of Christ. But is blood really the life of a man or is it light? (Read John 1) "In him was life, and that life was the light of all mankind..."

Abraham knew an ordinary lamb was not enough, he knew a human was not enough - God showed him that he would sacrifice his son just as he asked Abraham to enact the prophecy of sacrificing his son Isaac. It had to be a man who was without sin, a perfect man. But no man was found perfect, except Jesus - the son of God. Now that Jesus beat the game he gets to be judge over who gets what reward. Those who believe that he is the son of God, born in flesh, who died and rose back to life and ascended to heaven know the truth - that he gave his life and took away our sin and died so that we can have his life and live with him as children of god for ever. Those who don't believe in him get judged for their sins as usual.