"Then Jesus said to them, “Most assuredly, 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 eats My flesh and drinks My blood has eternal life, and I will raise him up at the last day. For My flesh is food indeed, and My blood is drink indeed. He who eats 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 he who feeds on Me will live because of Me. This is the bread which came down from heaven—not as your fathers ate the manna, and are dead. He who eats this bread will live forever.”
These things He said in the synagogue as He taught in Capernaum.
Therefore many of His disciples, when they heard this, said, “This is a hard saying; who can understand it?”
When Jesus knew in Himself that His disciples complained about this, He said to them, “Does this offend you? What then if you should see the Son of Man ascend where He was before? It is the Spirit who gives life; the flesh profits nothing. The words that I speak to you are spirit, and they are life. But there are some of you who do not believe.”
For Jesus knew from the beginning who they were who did not believe, and who would betray Him. And He said, “Therefore I have said to you that no one can come to Me unless it has been granted to him by My Father.”
From that time many of His disciples went back and walked with Him no more. Then Jesus said to the twelve, “Do you also want to go away?”
But Simon Peter answered Him, “Lord, to whom shall we go? You have the words of eternal life.
"https://www.biblegateway.com/passage/?search=John+6&version=NKJV