John 6.
Then many of his disciples who were listening said, "This saying is hard; who can accept it?" Since Jesus knew that his disciples were murmuring about this, he said to them, "Does this shock you? What if you were to see the Son of Man ascending to where he was before? It is the spirit that gives life, while the flesh is of no avail. The words I have spoken to you are spirit and life."
Jesus clarifies his metaphor earlier in John 6 with the saying "the words I have spoken to are spirit and life". His words are life, and spirit; he is the figurative Word of God. Remember how the Gospel of John begins:
In the beginning was the Word, and the Word was with God, and the Word was God. He was in the beginning with God. All things came to be through him, and without him nothing came to be. What came to be through him was life, and this life was the light of the human race; the light shines in the darkness, and the darkness has not overcome it.
Jesus is the Word; through Him comes life. He is not a literal "dictionary" or "book", he is the embodiment of the Scriptures, part of the Trinity.
Jesus taught in parables and metaphors. He even states as much in John 6 when he clarifies/simplifies for the disciples. We should not be like them (or Nicodemus) and take the words as literal!
Communion isn’t required to be saved. All thats required is to confess you are a sinner, declare Jesus is your savior and ask for forgiveness. You don’t even really need a priest or a pastor although having guidance does help many as they work out their issues.
Eph 2:8-9
8For it is by grace you have been saved, through faith—and this not from yourselves, it is the gift of God— 9not by works, so that no one can boast.
John 6:46-51
46No one has seen the Father except the one who is from God; only he has seen the Father. 47I tell you the truth, he who believes has everlasting life. 48I am the bread of life. 49Your forefathers ate the manna in the desert, yet they died. 50But here is the bread that comes down from heaven, which a man may eat and not die. 51I am the living bread that came down from heaven. If anyone eats of this bread, he will live forever. This bread is my flesh, which I will give for the life of the world.”