The bible is not the sole source of your form of Christianity. You still have your very own traditional interpretations.
And that's not enough. You're not getting Christ. As Christ said himself, Unless you eat the flesh of the Son of Man and drink his blood you have no life in you. John 6:53-56.
In that passage that you are referring to, Jesus is going back to what happened earlier that day and way back in history of Israel. First he referred back to the time when he fed the five thousand men plus women and children. The people sought after Jesus because they were fed and this how Jesus gets their attention onto bread.
26 Jesus answered them and said, Verily, verily, I say unto you, Ye seek me, not because ye saw the miracles, but because ye did eat of the loaves, and were filled.
27 Labour not for the meat which perisheth, but for that meat which endureth unto everlasting life, which the Son of man shall give unto you: for him hath God the Father sealed.
28 Then said they unto him, What shall we do, that we might work the works of God?
29 Jesus answered and said unto them, This is the work of God, that ye believe on him whom he hath sent.
He was leading them onto an important truth that if you believe on the Son, then you will have everlasting life. That is the whole point of the bread from heaven, since it gives us eternal life
And more importantly he was going back the time when the Israelites had manna. He was comparing himself to the manna. He was saying that those who ate from this bread from heaven are now dead, but those who eat from the true bread of heaven will not perish.
49 Your fathers did eat manna in the wilderness, and are dead.
50 This is the bread which cometh down from heaven, that a man may eat thereof, and not die.
51 I am the living bread which came down from heaven: if any man eat of this bread, he shall live for ever: and the bread that I will give is my flesh, which I will give for the life of the world.
Clearly he is making a reference to that occasion and that he is not literally bread and wine, but figuratively because he is making picture that he is the giver of life and that the previous bread does not satisfy.
Also you need to understand the time of the year that this happened. This happened close to the time of the Passover, so the significance is very great. In the Passover it was forbidden to have any leaven bread in the ceremony
Exodus 13:3 And Moses said unto the people, Remember this day, in which ye came out from Egypt, out of the house of bondage; for by strength of hand the LORD brought you out from this place:
there shall no leavened bread be eaten.
Absolutely no leaven or any product that had been through a fermentation process was not allowed in this ceremony, which includes all Alcoholic beverages since they go through fermentation to get the alcohol content. This is important to know because this is the exact time the Jesus gave the institution of the Lord's Supper. The two symbols in this ordinance are pointing to what Christ did on the cross. First of all his body was broken for our sins.
Isaiah 53:5 But he was wounded for our transgressions, he was bruised for our iniquities: the chastisement of our peace was upon him; and with his stripes we are healed.
So clearly the Lord's supper is a symbolic meal that is looking back at what Christ did for us. The bread and grape juice are not the blood and body of Christ and neither to they contain Christ. They are a representation of his redeeming work at calvary.
