For starters, you read the Bible. The whole Bible. From cover to cover. Over and over. And while you read it, you pray. You pray to the very God that provided the Bible for YOU to read. You pray directly to Him. Over and over. He will show you how to understand His Word. Have faith in His plan and your own God given intelligence. He hasn't provided His children with guidance that only a few can understand. It is very sad that you think you must have human interpretation to understand God's Word. What an incredible limit you've placed on your relationship with God.
With regard to John 6:53... Interpreting Scripture requires far more than examining a single verse offered without any other context. If I asked you to interpret a single sentence from the U.S. Constitution or Declaration of Independence, without offering the context of the entire document, your interpretation would most likely be incorrect. Similarly, if you are asking someone to interpret a single Scriptural verse, without providing the context in which it was written you most likely will get childlike answers, or confused, poorly supported doctrine. Therefore, rather than searching for the "right" interpretation of John 6:53, I suggest you first read the Bible. Then study the New Testament. Then examine the book of John, and you too will discover John 6:53 requires very little interpretation at all. You will know that when Jesus says "Verily, verily, I say unto you, Except ye eat the flesh of the Son of man, and drink his blood, ye have no life in you." he is not talking about some cannibalistic ceremony. You will know that the Jews Jesus was addressing were asking exactly the same questions you are. You will read His entire answer to them, rather than a single sentence of His answer. And you will wonder why in the world someone raised in a Christian Church could not realize that Scripture is to be read in its whole context. Not as cut and pasted snipets with accompanying doctrinal clarifications from Catholic texts. Have faith in God and the intelligence he gave you. You will be amazed at what He is capable of revealing to you...without the "help" of the Church.
You misunderstand! I don't want to argue with you about the doctrine of the Eucharist! We have different interpretations, and on that point, you and I are probably unmovable!
My point is, if private interpretation is always legitimate, then how come there are differences on such a pivotal issue? Now you must admit that there are Doctors of Scripture in the Catholic Church. They read the Bible over and over, cover to cover, study, and pray, and meditate, doing all the things a proper Christian is supposed to do with the Bible. And yet their interpretation of the Bible is so radically different from the Protestant one!
Now, you might say "well, they were reading the Bible with the eyes of the Catholic Church," and you would be right. But what about the Protestants who convert to Catholicism? Their faith may even have a vaguely anti-Catholic ring to it, and their relationship is with the Bible first. They read it cover to cover, study and pray and meditate, and come to a completely different conclusion than the one they have been taught all their lives.
Some Catholics leave their faith because they read the Bible, cover to cover, study, pray and meditate, and reject the Church's interpretation of John in favor of their own private interpretation which favors a less literal meaning.
I don't want you to explain to me why one is right and one is wrong. I want you to explain to me why, if private interpretation is all you need to understand the Bible, why two people who study the Bible privately come to such vastly different conclusions about such an incredibly important, central issue.