Well does Jesus say his words in John 6 are subject to interpretation? Does the inspired author label his words as a parable, as they are elsewhere in scripture?
Sola Scriptura is one of your standards, how does it work with your assumptions here?
Well,here's how it works:
When Jesus said he was the "door to the sheepfold", did he have to remember to explain he wasn't a real door? When Jesus said he was the "bread of life", did he have to be sure to add he wasn't saying he could be baked in an oven and used for a sandwich? When he taught that he was the "water of life" and whoever drank of him would never thirst, did he have to include that he didn't mean his bodily fluids could be dispensed and literally drunk? The obvious answer is no, of course not. The Jewish people were accustomed to the use of idioms and symbolical language. They grew up with Almighty God Jehovah likening himself to a mother hen guarding her chicks and as a husband who must deal with an unfaithful wife among other types. Somehow, I just don't think Jesus thought that he would have to explain OBVIOUS simile's. There was no need for him to "label his words as a parable", because the manner in which he taught THIS lesson was not the same as his parables. They just got it that he was not, could not possibly, be meaning his literal flesh and blood had to be physically consumed.
It was only centuries later that certain theologians started trying to interpret this lesson as literal and came up with the idea that explained how the bread and wine of the Lord's Supper observance actually became the real flesh and blood of Christ in order to make such a "sacrament" a regular and obligatory act necessary to BE saved. And, of course, they had to develop the "laws" that governed who was legitimately able to confect such miraculous changes and the office of the Catholic priesthood was born. But to insist that this doctrine was ALWAYS and EVERYWHERE believed in the same way by everyone, is simply false.
You were also already told, "As for why we see Jn. 6 as figurative, see one of the recent debates like here and here and links.
And you will not escape answering me by asking for what was already provided you.
Since you invoked Jn. 6:53 which plainly states, "Then Jesus said unto them, 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." (John 6:53) and as you hold this to be literal, then you must believe that one can have no life in himself unless he physically consumes the Lord's literal flesh, and otherwise he remains dead. Correct?
For Catholics, shame on us for arguing, when we know better. At least I am guilty of pride, when having rocks thrown by at least equally imperfect sinners. Sometimes you just have to laugh and let it go.
Titus 3:9-11 But avoid foolish controversies, genealogies, dissensions, and quarrels about the law, for they are unprofitable and worthless. As for a person who stirs up division, after warning him once and then twice, have nothing more to do with him, knowing that such a person is warped and sinful; he is self-condemned.
Proverbs 20:3 It is an honor for a man to keep aloof from strife, but every fool will be quarreling.
Proverbs 17:14 The beginning of strife is like letting out water, so quit before the quarrel breaks out.
2 Timothy 2:23 Have nothing to do with foolish, ignorant controversies; you know that they breed quarrels.
2 Timothy 2:14 Remind them of these things, and charge them before God not to quarrel about words, which does no good, but only ruins the hearers.
Proverbs 26:21 As charcoal to hot embers and wood to fire, so is a quarrelsome man for kindling strife.
1 John 2:1-29 My little children, I am writing these things to you so that you may not sin. But if anyone does sin, we have an advocate with the Father, Jesus Christ the righteous. He is the propitiation for our sins, and not for ours only but also for the sins of the whole world. And by this we know that we have come to know him, if we keep his commandments. Whoever says “I know him” but does not keep his commandments is a liar, and the truth is not in him, but whoever keeps his word, in him truly the love of God is perfected. By this we may know that we are in him: ...
James 4:1 What causes quarrels and what causes fights among you? Is it not this, that your passions are at war within you?
James 4:2 You covet and cannot obtain, so you fight and quarrel. You do not have, because you do not ask.
1 Corinthians 13:5 Or rude. It does not insist on its own way; it is not irritable or resentful;
Proverbs 21:19 It is better to live in a desert land than with a quarrelsome and fretful woman.
There are many more, and really we Catholics should know better.