John 6:53-69 ESV
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. Whoever feeds on my flesh and drinks my blood has eternal life, and I will raise him up on the last day. For my flesh is true food, and my blood is true drink. Whoever feeds on my flesh and drinks my blood abides in me, and I in him. As the living Father sent me, and I live because of the Father, so whoever feeds on me, he also will live because of me. This is the bread that came down from heaven, not like the bread the fathers ate, and died. Whoever feeds on this bread will live forever.” Jesus said these things in the synagogue, as he taught at Capernaum.
When many of his disciples heard it, they said, “This is a hard saying; who can listen to it?” But Jesus, knowing in himself that his disciples were grumbling about this, said to them, “Do you take offense at this? Then what if you were to see the Son of Man ascending to where he was before? 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. But there are some of you who do not believe.” (For Jesus knew from the beginning who those were who did not believe, and who it was who would betray him.) And he said, “This is why I told you that no one can come to me unless it is granted him by the Father.”
After this many of his disciples turned back and no longer walked with him. So Jesus said to the twelve, “Do you want to go away as well?” Simon Peter answered him, “Lord, to whom shall we go? You have the words of eternal life, and we have believed, and have come to know, that you are the Holy One of God.”
ESV: English Standard Version 2016