Did Jesus break Old Testament Law by telling his followers to drink his blood?
Jews were prohibited from drinking blood by the Old Testament. So if the Catholic idea about the Eucharist as the "Blood of Christ" is correct, didn’t Jesus break the Law of God?
Nope. He fulfilled it. "The blood is the life," as the Torah taught the Jews, and the life of a creature belongs to God. Hence the Jews were to pour the blood out on the earth, not because it was too vile but because it was too sacred. They were to seek their life, not from any creature, but from God himself. How fitting then that when Jesus (Who is the Life [Jn 14:6]) comes we are commanded to drink his blood (Mt 26:27–28). His is the blood we not only may but must drink if we are to have life in us (Jn 6:53). It is the reality of which all other blood is an image (Heb 9).