Jesus said,
(John 6:53-56 ESV) 53 So Jesus said to them, “Truly, truly, I say to you, unless you eat the flesh of the Son of Man and drink his blood, you have no life in you. 54 Whoever feeds on my flesh and drinks my blood has eternal life, and I will raise him up on the last day. 55 For my flesh is true food, and my blood is true drink. 56 Whoever feeds on my flesh and drinks my blood abides in me, and I in him.
(John 6:63 ESV) 63 “It is the Spirit who gives life; the flesh is no help at all. The words that I have spoken to you are spirit and life.”
(John 6:68-69 ESV) 68 Simon Peter answered him, “Lord, to whom shall we go? You have the words of eternal life, 69 and we have believed, and have come to know, that you are the Holy One of God.”
Add to this list the following from the Torah, too well known to require John to mention it —
(Lev 17:14a ESV) For the life of every creature is its blood: its blood is its life.
(among many other occurrences in the Torah).
Hence, we have Jesus’ blood = (eternal) life; Spirit = life; Jesus’ words = life; Jesus’ words = spirit. And, of course, both the Hebrew and Greek words for “spirit” can be translated “breath” and so are often used as metaphors for, you guessed it, life.
You have to figure the topic is eternal life, coming via the Spirit and Jesus’ words. That is, after all major theme of John.
Passover as a key to interpretation
Now, what would have made this all much clearer is if Jesus has explicitly referred to the Passover, because the Passover connects drinking symbolic blood with God’s covenant with his elect people.
Ah, but John begins the presentation with —
(John 6:4 ESV) 4 Now the Passover, the feast of the Jews, was at hand.
You see, John is giving us the key to interpretation. This is no mere chronological marker, to satisfy our curiosity about time (much more of a concern to a Western audience). No, this is the key to understanding. It where the metaphors are defined.
Here’s my take, but knowing both John and Jesus, I’m sure there are other takes possible that are equally — even more — valid.
“The life of every creature is its blood.” The ancient Jewish practice, commanded most stringently by God himself, is to not drink blood. Why not? Because the life is in the blood. Why does that matter?
Well, there was an ethical element: it would be cruel to eat the flesh of an animal while it’s still alive (which was apparently a practice of some pagan cults (horrors!)). Moreover, it was a sign of thanksgiving. The Jews poured the blood of the slaughtered animal on the ground as a thanks for the life taken in order to provide life. Life for life. (Cf. Gen 35:14; 1 Sam 7:6; 2 Sam 23:16-17).
The blood-pouring ritual applied to all slaughtering of animals, not just ritual sacrifice. Human life comes at a cost, the cost of animal life, and the ceremonial pouring out of the blood reminds the observant Jew of the cost.
Redefining “sacrifice”
To drink the “blood” of Jesus, therefore, redefines sacrifice in a radical way. The usual reason to eat a lamb sacrificed at Passover was to engage in fellowship with God, to symbolically eat a meal with him. This remains a key idea behind the Lord’s Supper.
But the Temple sacrificial system and the Passover meal were not about gaining eternal life — not directly. They were about atonement for sin and remembrance. Atonement, in New Testament theology, is very closely tied to eternal life, but that is not the idea in the Torah. Rather, Torah observance was to bring God’s blessings in this life. Deu 28 details the blessings that would result from obedience, and eternity with God is not there.
Hence, when Jesus uses language, symbolic though it is, changing the Passover from eating flesh to eating both flesh and blood, surely a key thought is that, now, the blood must be eaten because the sacrifice that Jesus would offer has the very explicit purpose to grant (eternal) life.
In the Old Testament, God had promised a Kingdom and a Messiah who would bring about the new heavens and earth and a resurrection. These new blessings require a new kind of sacrifice: both flesh and blood, because life now is a gift received from sacrifice.
We obtain our eternal life from Jesus. It’s not innate. We weren’t born eternal beings. Rather, it’s a gift we receive from the Messiah.
(Rom 2:7 ESV) 7 to those who by patience in well-doing seek for glory and honor and immortality, he will give eternal life;
Compare —
(2Ti 1:10 ESV) 10 and which now has been manifested through the appearing of our Savior Christ Jesus, who abolished death and brought life and immortality to light through the gospel,
(1Co 15:53 ESV) 53 For this perishable body must put on the imperishable, and this mortal body must put on immortality.
We tend to adopt the Platonic notion that we’re born with immortal souls, and so we spend our lives worrying about losing our existing immortality. But the scriptures say that we’re born mortal and receive immortality — life — as a gift.
Thus, our resurrection will be received by our consuming that sacrifice, including the blood, because the blood gives life, and life is only received through blood.
It’s not quite as simple as “life is in the blood,” but it’s close. The blood gives life, and so we must drink the blood to receive it.
Becoming a curse for Christ
What was once an abomination is now a blessing — indeed, a condition of immortality. But it’s the nature of the gospel to take Torah curses and turn them into new covenant blessings —
(Gal 3:13-14 ESV) 13 Christ redeemed us from the curse of the law by becoming a curse for us — for it is written, “Cursed is everyone who is hanged on a tree” — 14 so that in Christ Jesus the blessing of Abraham might come to the Gentiles, so that we might receive the promised Spirit through faith.
Just so, because of the Gospel, Jesus heals a lame man on a Sabbath in John 5 — which is literally a death penalty violation (Num 15:32-36). He becomes a curse in order to be a blessing. And to follow Jesus, we must be willing to become accursed in order to be blessed.
When we take communion, we aren’t drinking Jesus’ literal blood. Neither are we taking a sacrament that blesses by its own power. Rather, we’re re-committing to drink Jesus’ blood, that is, to receive his life by becoming a curse and an abomination. We commit to suffering slander, persecution, and even death for the sake of Jesus. We yield to the command to become living sacrifices.
We receive the immortality of Jesus by drinking his blood, where immortal life is found. We drink his blood by calling others to follow Jesus, rubbing elbows with Samaritans, healing on the Sabbath, feeding those who hunger for God and those who hunger for food, bringing forgiveness to sinners — even if it means we’re rejected by our families, our friends, even our congregations.
We take a drink that symbolizes an abomination and a curse to declare that we will gladly become accursed for Jesus, because he became accursed for us.