I've been reading an interesting article in Christian Century magazine about blood vengeance, blood sacrifice, etc. and the Christian faith. There's a long history of requiring that blood be shed for faith. Sacrifice a lamb and spread the blood on the doorpost to indicate the house belongs to God's chosen. Temple sacrifice. Sacrifice to appease angry gods. Baal. The Old Testament, particularly, is filled with examples of sacrifices.
The big example of blood sacrifice in the New Testament is Jesus' crucifixion. The questions raised in this article surround the motivation for the crucifixion. Does God require blood atonement for our sins? Must we suffer for our sins? By inference, do we suffer because we are sinners?
I prefer to think of the crucifixion as transformative rather than redemptive. I think of the Old Testament as primarily a story of God's faithfulness to God's unfaithful people. God constantly renews his covenant, his side of the bargain, even as the people return to sin whenever the going gets slightly rough. God is faithful, God's people are not. The crucifixion is yet another example of God's faithfulness, the ends to which God will go. Jesus dies, not so much to redeem us as to transform us to be the people God has always seen us to be -- people who live on earth as they would in heaven, to forgive others as we wish to be forgiven, to treat others as we would treat God.
Crucifixion is not blood sacrifice, but the ultimate renewal of the covenant, the ultimate transforming event.