One of the most important Catholic beliefs, the Eucharist refers to the bread and wine which Catholics believe are changed in the Mass into the actual Body, Blood, Soul and Divinity of Jesus Christ; and that Catholics are required to receive the Eucharist as a condition of their salvation. See John 6:22-66, in which Catholics translate Jesus's words literally. His teaching is NOT a parable as some believe.

"The Eucharist is "the source and summit of the Christian life. The other sacraments, and indeed all ecclesiastical ministries and works of the apostolate, are bound up with the Eucharist and are oriented toward it. For in the blessed Eucharist is contained the whole spiritual good of the Church, namely Christ himself, our Pasch."  --Catechism of the Catholic Church (1324)

My friend says Jesus was speaking metaphorically when He said, “This is my body.” How do I answer that?
by Steven O'Keefe, CAA Staff Apologist (11-10-23)

First, you should show you understand where he is coming from. We Catholics can act like the passage is perfectly clear when Jesus says, “This is my body” – as if there is no room for a metaphorical interpretation. However, suppose you were having dinner with the fellow and explaining a car crash you were in. You pick up a couple dinner rolls, put them in position on the table, and say, “OK, this is my car and this is her car.” In that context it is obvious you are using metaphorical language. The same can apply to Jesus’s words on Holy Thursday.
Instead, you should admit that if we only had those words to go by, then it really could go either way. But then you can point out that we have many other passages to help us understand what Jesus meant. Among them would be Saint Paul’s words in 1Corinthians 10:16, where he says: “The cup of blessing that we bless, is it not a participation in the blood of Christ? The bread that we break, is it not a participation in the body of Christ?”

Or in 1Corinthians 11:29 where he says: “Anyone who eats and drinks without discerning the body eats and drinks judgment on himself.” Then there is the bread of life discourse in John 6, where Jesus says: “I am the living bread that came down from heaven. If anyone eats of this bread, he will live forever. And the bread that I will give for the life of the world is my flesh.”

Thus, by understanding the totality of the Scriptural witness about the nature of the Lord’s Supper, we can tip the scales in balance of a literal understanding of what Jesus was saying.

How do we know the Bread of Life discourse in John 6 connects to the Last Supper?
by Steve O'Keefe, CAA Staff Apologist

The Bread of Life Discourse is an important passage for proving that the doctrine of the Eucharist is taught by the Bible. However, some non-Catholics point out that the Gospel’s author never specifically ties the passage to the Last Supper. In fact, John’s Gospel doesn’t even record Jesus instituting the Eucharist. So they call into question whether John 6 is a valid passage to help us understand Jesus’ words at the Last Supper.

The first thing I would point out is the inherent plausibility of connecting the two passages. You have one where Jesus is comparing His body to bread and saying people will have to eat His flesh. In the other you have Jesus holding bread, claiming it is His flesh, and giving it to people to eat. Also, both take place in the context of Passover.

Still, the question remains; Why didn’t John record the words of institution at the Last Supper and explicitly connect them to the Bread of Life Discourse? The simplest answer is he didn’t have to. John’s Gospel was written last, and he assumed his audience was already familiar with the other Gospels. That’s why in John 3:24 he says, “John the Baptist had not yet been put in prison” and in John 6:17, “It was now dark, and Jesus had not yet come to them [on the water].” In other words, John is intentionally writing his Gospel to
supplement what you already know from the others. Given this background, it shouldn’t be surprising that John omits something which was present in the other three Gospels and in Paul’s letters too.

In the end, there is no way to 100% demonstrate the connection between the two passages.You can show the plausibility of the connection and answer the arguments against it, but if a person refuses to see it, he won’t see it

A friend says Jesus was speaking metaphorically when He said, “This is my body.”  How do I answer that?
by Steven O'Keefe, CAA Apologist

First, you should show that you understand where he is coming from.  We Catholics can act like the passage is perfectly clear when Jesus says, “This is my body” – as if there is no room for a metaphorical interpretation.  However, suppose you were having dinner with the fellow and explaining a car crash you were in.  You pick up a couple dinner rolls, put them in position on the table, and say, “OK, this is my car and this is her car.”  In that context it is obvious that you are using metaphorical language.  The same can apply to Jesus’ words on Holy Thursday.

Instead, you should admit that if we only had those words to go by, then it really could go either way.  But then you can point out that we have many other passages to help us understand what Jesus meant.   Among them would be Saint Paul’s words in 1Corinthians 10:16, where he says: “The cup of blessing that we bless, is it not a participation in the blood of Christ? The bread that we break, is it not a participation in the body of Christ?”  Or in 1Corinthians 11:29 where he says: “Anyone who eats and drinks without discerning the body eats and drinks judgment on himself.”  Then there is the bread of life discourse in John 6, where Jesus says: “I am the living bread that came down from heaven. If anyone eats of this bread, he will live forever. And the bread that I will give for the life of the world is my flesh.”

Thus, by understanding the totality of the Scriptural witness about the nature of the Lord’s Supper, we can tip the scales in balance of a literal understanding of what Jesus was saying.  

A non-Catholic Christian told me John 6:63 disproves the Catholic doctrine of the Real Presence.  Does it?
As the Bread of Life Discourse is concluding, Jesus challenges the people for their lack of belief, saying: “Does this offend you? It is the spirit that gives life; the flesh is of no avail. The words that I have spoken to you are spirit and life” [John 6:63].  Many non-Catholics will seize upon this phrase as proving Jesus had only been speaking figuratively about the Eucharist being His body, intending it only in a spiritual or symbolic sense. 

One simple way to answer this objection is to pay close attention to the reactions of Jesus’ audience.  The crowd is horrified when Jesus proposes the eating of His flesh.  They said, “How can this man give us his flesh to eat?” and “This is a hard saying and who can hear it?”  [John 6: 52, 60]  They were practically begging Jesus to clarify his comments in a symbolic, merely spiritual light. Now, if Jesus intended to do precisely that in verse 63, why did the crowd remain scandalized and walk away?  And why did Jesus let them walk away on account of their supposed misunderstanding?  The answer is that whatever Jesus meant in verse 63, it did not de-literalize His words one bit.  The crowd continued thinking Jesus was speaking literally… and they were right.

So what did Jesus mean?  When Jesus says “the flesh is of no avail”, He is not referring to His own flesh, which was the instrument by which He redeemed the world.  He was using the word “flesh” in the same sense He uses it in John 8:15 and the way Paul uses it in Romans 8:6.  There it refers to the faculties of man’s fallen nature and the worldly standards by which we evaluate things.   It is those worldly faculties which cannot be relied upon to tell us the truth about the Eucharist.  What you detect with your senses is ordinary bread and wine.  But, indeed, the flesh is of no avail.