Then Jesus said unto them, Verily, verily, I say unto you, Except ye eat the flesh of the Son of man, and drink his blood, ye have no life in you. John 6:53
"Today, the rabbi discussed the absolute prohibition against eating blood. My question concerns [Jesus'] statement, "Unless you eat (my body) and drink (my blood) you have no part of me." How do you understand [Jesus'] seeming blatant denigration of eating/drinking blood when there is such a Jewish revulsion against this very idea?
Obviously [Jesus] wasn't telling his disciples to break the prohibition against eating blood by offering his own blood to drink. This is one of the so-called "hard sayings" of [Jesus]. A passage that sheds excellent light on these passages is 1 Samuel 23:17.
A couple of verses earlier, David was very thirsty at the encampment awaiting the battle with the Philistines. He made the comment, "Oh, that someone would give me water to drink from the well of Bethlehem which is by the gate." Then three of David's men broke through the camp of the Philistines and drew water out of the well of Bethlehem and brought it to David. However, David poured it out, saying, "Be it far from me, O YHWH, that I should do this. Shall I drink the blood of the men who went in jeopardy of their lives?" Now, obviously David's men weren't giving David their own blood to drink, but water from the well in Bethlehem.
Likewise, Yeshua didn't change the Passover wine into his own blood. At this time, Yeshua hadn't even had his blood poured out in the crucifixion at Golgotha. No, this is purely symbolic. When we partake of the wine (or grape juice if you prefer), we are drinking wine or grape juice, not the blood of [Jesus].
However, symbolically we identify it with the blood of [Jesus]. Likewise, when we partake of the...matzo, we are eating unleavened bread, not the literal body of [Jesus], which would be tantamount to cannibalism. It was also not his intention to turn us into cannibals.
However, symbolically, we are partaking of [Christ's] crucified body, which the matzo [cracker-like bread] symbolizes so clearly with its pierce marks, stripes, and "bruises," clearly foreshadowed by Isaiah 53:5. I trust that this clears up your questions. "