Suppose I rushed up to you , all excited, and said, “The most incredible thing has happened! Sit down, because you are going to be astounded! I know some of this is going to be hard to believe, but you’ve got to understand, I’m not making this up! I saw it with my own eyes.”
And what I have seen with my own eyes, what my hands have handled, is the very Word of life itself. " God has become man, died on the cross and been raised from the dead! Now he makes himself available to us in the most intimate communion possible in this life, through the sacrament of His Most Holy Body and Blood! I saw it ,I tell you. this is no myth! This really happened!"
what would you think if I then sat down and proceeded, in answer to your many questions about this hard-to-buy story, to invent “sayings and acts” of Jesus out of complete whole cloth, and attribute them to Christ.
I suspect your reaction would be like most people’s. You’d recognize me as, at best, deluded and (more honestly) as a pathological liar.
Some folks do not see what the problem is. They see no substantial difference saying the Gospel writers paraphrased Jesus and saying they made up entire stories and sayings, affirmed them as Gospel truth and told us to believe them on pain or hellfire. Why, they ask, couldn’t this process be guided by The Holy Spirit too.
The basic answer is that this process is normally known as “lying”. But The Gospels are not a lie undertaken for our good. The Gospels are telling us what Jesus said and did.
The Gospels are, after all, Greek accounts of conversations that largely took place in Aramaic. Moreover, the materials in The Gospels are arranged by the writer with real editorial control in order to make particular points. So when Matthew takes certain sayings of Jesus and informs us that they were said on a mountain, he has a theological purpose: he wants us to understand that Jesus is the New Moses for the Jewish people.
Likewise when Luke’s Jesus speaks the same batch of sayings on a level place, he wants us to understand that Jesus is the Son of Man and the Saviour of all people who has joined us in our low estate. that’s because the purpose of The Gospels is to arrange real historic materials to make a theological point, not to chronical Jesus’ every word and deed. Indeed The Gospels barely cover 100 days in the entire life of Jesus. But what they cover actually happened.
That said, it is simply false to posit the choice, "Either every single word of The Gospels exactly reproduces the tape-recorded saying of Christ or else we are free to believe that The Apostles just made up a bunch of junk Jesus never said and attributed it to Him."
The teaching of the Church is basically that John 6 preserves the substance of real things said by Jesus in a conversation with the crowd at Capernaum. the teaching of the Church is not, “John just made up a bunch of baloney and attributed it to Jesus to get himself out of a pastoral jam.” It is that the Gospels are reliable accounts of the life, teaching, death, and resurrection of Jesus Christ.