But he doesn’t say the contents of the cup is symbolic of his blood. He says it IS his blood. And of course, it is the same blood as the blood he was about to shed the following day.
Jer 15:16 Thy words were found, and I did eat them; and thy word was unto me the joy and rejoicing of mine heart: for I am called by thy name, O LORD God of hosts.
And God didn't say his words were symbolic of food...
Eze 3:1 Moreover he said unto me, Son of man, eat that thou findest; eat this roll, and go speak unto the house of Israel.
Eze 3:2 So I opened my mouth, and he caused me to eat that roll.
Eze 3:3 And he said unto me, Son of man, cause thy belly to eat, and fill thy bowels with this roll that I give thee. Then did I eat it; and it was in my mouth as honey for sweetness.
Eze 2:8 But thou, son of man, hear what I say unto thee; Be not thou rebellious like that rebellious house: open thy mouth, and eat that I give thee.
Eze 2:9 And when I looked, behold, an hand was sent unto me; and, lo, a roll of a book was therein;
Eze 2:10 And he spread it before me; and it was written within and without: and there was written therein lamentations, and mourning, and woe.
Perhaps if your teachers had read and believed the bible they would know that examples were given thru out scripture how to understand those scriptures that do not literally make sense...
1Pe 2:2 As newborn babes, desire the sincere milk of the word, that ye may grow thereby:
1Co 3:1 And I, brethren, could not speak unto you as unto spiritual, but as unto carnal, even as unto babes in Christ.
1Co 3:2 I have fed you with milk, and not with meat: for hitherto ye were not able to bear it, neither yet now are ye able.
1Co 3:6 I have planted, Apollos watered; but God gave the increase.
1Co 3:7 So then neither is he that planteth any thing, neither he that watereth; but God that giveth the increase.
1Co 3:8 Now he that planteth and he that watereth are one: and every man shall receive his own reward according to his own labour.
The bible is milk and meat, We are plants in a garden, bread and wine is flesh and blood, we will never thirst again...
Heb 6:5 And have tasted the good word of God, and the powers of the world to come,
I'd say a lot less time studying human philosophy and a lot more time studying the scriptures is good for the soul...