This is a very interesting conundrum for Christians. Leviticus 17:14 says:
For the life of every creature - its blood is its life. Therefore I said to the people of Isra'el, 'You are not to eat the blood of any creature, because the life of every creature is its blood. Whoever eats it will be cut off.'
Apparently blood is so vile this bears repeating in chapter 19:26 "Do not eat anything with blood."
If Christ is supposed to be the sacrificial lamb, and drinking his blood is salvation, what does this say about the book of Leviticus? What does it say about Christianity? What does it say about Christ's theology? What does it say about the group called "Jews for Jesus?" What does it say about the Eucharist? What does it say about Christ being the "sacrificial lamb?"
17: 4-7 shows how blood is supposed to be used during sacrifices:
the people of Isra'el will bring their sacrifices that they sacrifice out in the field -so that they will bring them to ADONAI, to the entrance of the tent of meeting, to the cohen, and sacrifice them as peace offerings to ADONAI. 6 The cohen will splash the blood against the altar of ADONAI at the entrance to the tent of meeting and make the fat go up in smoke as a pleasing aroma for ADONAI. 7 No longer will they offer sacrifices to the goat-demons, before whom they prostitute themselves! This is a permanent regulation for them through all their generations.
This doesn't sound like what Jesus meant. He was clearly either starting a new tradition or inserting a different cultural practice into his Judaism. If his sacrifice on the cross is supposed to be represented by his blood he should be commanding his followers to splash blood on the altar. His "Last Supper" doesn't sound much like a Passover Seder, either, since blood would be splashed on a doorway... and could not have been eaten as part of the meal.
Where did this cannibalistic ritual come from? In the O.T. people sacrificed their children, but God supposedly condemned that as a foreign practice. And cannibalism was a form of punishment or a way to deal with hunger after being smote by God. So God certainly shouldn't have done it himself. Sacrifice as atonement for sins by offering a burnt animal took place only at the Temple, and the sacrifice was given by sinners to the priests. Jesus didn't offer to have himself burned, or offer burned flesh to the disciples.
It's easy to see why this new cult had trouble convincing Jews to join. This supposed rabbi was teaching something totally unorthodox and repulsive to them.