Not meant to be funny. Proof for the Roman Catholic understanding is not there unless one practices eisegesis.
Jesus often used hyperbole in His dealings with people.
Jesus told people to gouge out their eye or cut their hand off if it caused them to sin.
Jesus told the young ruler to sell his possessions and follow Him.
I don't see any maimed Roman Catholics or any RCs who've sold all of their stuff.
Roman Catholics want to take Jn 6:52-57 as literal yet ignore these statements by Christ.
In John 6 they take 6:52-57 as literal yet not this passage from the same chapter:
35Jesus said to them, I am the bread of life; he who comes to Me will not hunger, and he who believes in Me will never thirst.
Here Roman Catholics do not apply the literal interpretation to the passage.
Why?
But all of this ignores the simple message of not only this passage but of John, Matthew, Mark, Luke and the NT.
Belief in Him for salvation.
35Jesus said to them, I am the bread of life; he who comes to Me will not hunger, and he who believes in Me will never thirst. 36But I said to you that you have seen Me, and yet do not believe. 37All that the Father gives Me will come to Me, and the one who comes to Me I will certainly not cast out. 38For I have come down from heaven, not to do My own will, but the will of Him who sent Me. 39This is the will of Him who sent Me, that of all that He has given Me I lose nothing, but raise it up on the last day. 40For this is the will of My Father, that everyone who beholds the Son and believes in Him will have eternal life, and I Myself will raise him up on the last day. John 6:35-40 NASB
Jesus continues this theme:
. 46Not that anyone has seen the Father, except the One who is from God; He has seen the Father. 47Truly, truly, I say to you, he who believes has eternal life. 6:46-47
He continues the theme of belief but now clarifies the meaning of what He's been saying:
63It is the Spirit who gives life; the flesh profits nothing; the words that I have spoken to you are spirit and are life. 64But there are some of you who do not believe. For Jesus knew from the beginning who they were who did not believe, and who it was that would betray Him. 6:63-65
The disciples who remained with Him understood it was about belief in Him that lead to salvation....not eating/drinking flesh and blood.
67So Jesus said to the twelve, You do not want to go away also, do you? 68Simon Peter answered Him, Lord, to whom shall we go? You have words of eternal life.
69We have believed and have come to know that You are the Holy One of God. 6:67-69.
It is the consistent message of the NT....believe in Him for salvation.
In no other passage where the Gospel is mentioned is it ever said a person must eat/drink the flesh/blood of Jesus for salvation.
It is always about coming to Christ through belief in Him.
If it is not about belief in Him for salvation, then Jesus lied to Nicodemos.
We all know that Jesus sometimes used parables, similes, Semitic hyperbole and all the rest. There are three ways to tell when He's doing that:
For instance, Jesus said to pluck out your eye or cut off your foot rather than let it lead you into sin. Nobody did that, and the one guy who (his enemies allege) did maim himself, Origen, had always interpreted Jesus' words in that very passage allegorically. Origen wrote vehemently that anyone who would do such a thing would be an idiot.
You don't once show that these criteria apply to the Lord's realism about His Body being real food, and His blood being real drink, because you can't.
There is a related, but separate question, whether one must receive Holy Communion ("eat and drink the Body and Blood of the Lord") in order to have eternal life.
Examining Scriptures, How Scripture proclaims we are saved:
By believing in Jesus Christ (Jn 3:16; Acts 16:31)
By repentance (Acts 2:38; 2 Pet 3:9)
By baptism (Jn 3:5; 1 Pet 3:21; Titus 3:5)
By eating His flesh and drinking His blood (Jn 6)
By the work of the Spirit (Jn 3:5; 2 Cor 3:6)
By declaring with our mouths (Lk 12:8; Rom 10:9)
By coming to a knowledge of the truth (1 Tim 2:4; Heb 10:26)
By works (Rom 2:6-7; James 2:24)
By grace (Acts 15:11; Eph 2:8)
By His blood (Rom 5:9; Heb 9:22)
By His righteousness (Rom 5:17; 2 Pet 1:1)
By keeping the commandments (Matt 19:17)
By our words (Matt 12:37)
By compassion toward the needy (John 10:25-37; Matthew 25:31-46)
By enduring to the end (Matt.24:13)
All those things comprise the ramifications and consequences, the fully-developed meaning of one single thing: having "faith in Christ." Faith, fully understood, means being incorporated into Christ. It includes all the things I quoted from Scripture, above, and Scripture never lies. The above are the ways in which we have faith, because they are the ways we are faithful. They are the ways we grow in His grace and become more and more incorporated into Christ.
This is a living, working, active and growing faith, not easy-believe-ism or what some call "faith alone," a merely verbal and notional faith.
But "Faith alone"?
--- True, that exact phrase is used by the Apostle James, and is found in the Bible just once: I quote it in my tagline.