There is Life in the Blood
If anyone of the house of Israel or of the aliens who reside among them eats any blood, I will set my face against that person who eats blood, and will cut that person off from the people. For the life of the flesh is in the blood; and I have given it to you for making atonement for your lives on the altar; for, as life, it is the blood that makes atonement. Leviticus 17:10-11
Then he took a cup, and after giving thanks he said, "Take this and divide it among yourselves; for I tell you that from now on I will not drink of the fruit of the vine until the kingdom of God comes." Then he took a loaf of bread, and when he had given thanks, he broke it and gave it to them, saying, "This is my body, which is given for you. Do this in remembrance of me." And he did the same with the cup after supper, saying, "This cup that is poured out for you is the new covenant in my blood. Luke 22:17-20
Above are two passages that can be found in areas of the Bible where communities are being formed. In the Old Testament God supplies laws for the formation and sustaining of the community; the obedience of these laws will set them apart from the surrounding pagan communities. The one referenced above (Leviticus) speaks to the issue of blood consumption. They were not to consume the blood of any animal or they would be "cut off" from the community. "For the life of the flesh is in the blood,"and the life-blood was to be reserved for atonement for the lives of the children of Israel.
Fast forward several thousand years and we find another community being formed; a new Israel, if you will. And here Jesus, THE Israelite, is telling his disciples that they will be unified by actually drinking his blood (we understand, of course, that it was not real blood). They were to drink his blood for the same reason the Israelites in the Old Testament were told not too. "For the life of the flesh is in the blood, and [God the Father] has given it to you for your lives...]
It's beautiful what happens when we read the Old and New Testament in tandem.