Good morning Patience,I am so sorry for getting back to you after such a long delay. Nonetheless, I hope that these brief responses provide sufficient substance for your continued reflection.
QUESTION, Part 1: When he gave the bread, he said "This is my body, do this in remembrance of me." But in John 6, he repeatedly says, that unless you drink his blood and eat his flesh you can no part of him. So if when he was in the upper room the bread was to be his flesh... why didn't he use the word flesh specifically?
RESPONSE 1: It appears to me that our Lord's decision to use the word body/soma rather than flesh/sarx while instituting the Blessed Sacrament of His Body and Blood was taken in an effort to avoid confusion. In the NT era the term sarx/flesh was often used as a means of referring to one of the forces of evil that the Christian wages war against in his effort to overcome sin. [See the Apostle Paul's use of the term in Romans 8 (especially verses 1-9).] By using the term soma/body our Lord avoided several potential but very real misunderstandings that could follow from the use of the word sarx/flesh.
RESPONSE 2: A second reason why our Lord probably may have opted for the term soma/body in favor of flesh/sarx is related to the content of the Church's dogma regarding the nature of the Eucharistic Feast. Since in the Sacrament of the Eucharist Christians receive "the body, blood, soul and divinity" of our Lord and Savior Jesus Christ, it is more fitting that our Lord should use that term of reference to humanity's bodily existence which embraces the fullness of the person (soma), rather than a term that typically refers to humanity's bodily existence as a distinct aspect of that existence (flesh).
QUESTION, Part 2: Also, does this mean, that if you are not a catholic you cannot go to heaven since you don't get to eat his body and drink his blood? Why or why not?
RESPONSE: Yes. Our Lord's words appear quite clear on the matter. Anyone who understands Jesus' words concerning the necessity of eating his flesh and drinking his blood and refuses to accept this means of grace imperils his soul and wills not to enter into heaven.
[Note: This answer does not speak to the question of men and women who for no fault of their own are invincibly ignorant of the significance of our Lord's words. In all such cases, the Catholic can be confident that "the judge of all the earth will do right" (See Genesis 18:25).]
Many blessings,
Vaughn
