Dear G,
Let’s look at the context. Jesus has just emphatically said, to the extreme consternation of most of those listening, that His flesh is real food and His blood is real drink. Anyone who would eat His flesh and drink His blood will live forever. It doesn’t make any sense that He would then completely contradict what He has just said.
However, He was fully aware of the difficulty they had in accepting His words on the matter. His words about the bread reveal something real and divine of which only the spirit can supply understanding and which is the source of life for men. So He says: “It is the spirit that gives life, the flesh has nothing to offer. The words I have spoken to you are spirit and they are life.” (Jn 6” 63) Without the help of the spirit, we lack the gift of faith. “’But there are some of you who do not believe.’ For Jesus knew from the outset those who did not believe, and who it was that would betray Him. He went on, ‘This is why I told you that no one could come to me unless the Father allows him.’ After this, many of His disciples left him and stopped going with Him.” (John 6: 64-66) So you see, that verse 63 makes perfect sense. Peter could affirm that only Jesus has the message of eternal life because the Father revealed this to him through the Spirit.
In Matt 16:16-19 Peter again manifests his faith and this time Jesus says, "Simon son of Jonah, you are a happy man! Because it was not flesh and blood that revealed this to you, but my Father in heaven. So I now say to youu: You are Peter and on this rock I will build my Church. And the gates of the underworld can never hold out against it.
Fr. Vincent Serpa, O.P.
