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.
John 6:53
Surrounding context
6:52 The Jews therefore quarreled among themselves, saying, "How can this Man give us His flesh to eat?"
6:53 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.
6:54 Whoever eats My flesh and drinks My blood has eternal life, and I will raise him up at the last day.