This is the favorite of apologists trying to show Paul’s knowledge of at least some event in the gospel stories. It is also one of the texts most often suggested to be an interpolation. That being said, it is very easy while wearing gospel glasses to read the story of the upper room and betrayal back into this text. As an aside, I would point out that the translators are not immune from this tendency. Notice in your quote, it says “he was betrayed”. The Greek text doesn’t say this. Rather, it says “handed over”. The mental picture of the translators gives the impression of a meeting of disciples and Judas, but that isn’t there. There are extensive studies showing how Mark took Pauline teachings and “historicized” them, putting them into a time and place with narrative details, this being one example. Notice that Paul doesn’t suggest that he had heard this story from anyone. As usual, he got it by revelation. Paul’s discussion looks suspiciously like the contemporary Greco-Roman mystery religions with their own dying and rising savior gods, celebrated with sacred meals.
There was only one story, that of the unknown author of the Gospel of Mark. In no way can the others be considered to be independent sources. Rather, they are dependent upon Mark, embellished with legendary details and correcting each other. It would appear that Paul’s cosmic Christ became historicized by Mark’s allegory which was then misunderstood by Matthew as actual history, embellished, then corrected by Luke who didn’t like Matthew’s theology (too Jewish). It is important to remain aware that eyewitnesses have no need to copy the story of another, as was done with Mark’s narrative. They simply felt free to add details to the story to make it more fantastic, often contradicting each other.
The way historians use sources also reflects on the validity of their reports. You had mentioned in a previous response that
OK, I will show you one such “written fragment” on which the gospel writers were dependent.
We have a source unrelated to the gospels from a non-Christian writer:
The account tells us of a peasant named Jesus who appeared during the holy days and foretold the destruction of the temple, the city of Jerusalem, and a time of trouble for its people. He predicted his own imminent death. The leaders of the Jews arrested him, beat him, and interrogated him. He refused to speak or answer their accusations in any way. The Jewish leaders wished to do away with him for his prophecies against the temple and the city, so they took him to the Roman governor making accusations against him. The Roman governor questioned Jesus, yet he opened not his mouth. He refused to curse or blame his accusers. The Roman governor wondered if Jesus had some godly spirit associated with him. When he could get no defense from Jesus, and thinking him not guilty of any crime, consented to have him scourged to the bone to placate the Jewish mob.
The parallels to the apocalyptic prophecy of Jesus in the gospels and the following arrest, accusations, trial, and scourging by the Roman governor, in the same order and for the same reasons, are simply too close to be coincidence. Did the gospel writers get the inspiration for their story from this account? It would appear so. But who was this Jesus? It was Jesus ben Ananus whose story was recounted by Josephus who wrote,
"Four years before the war, when the city was enjoying profound peace and prosperity, there came to the feast at which it is the custom of all Jews to erect tabernacles to God, one Jesus, son of Ananias, a rude peasant, who suddenly began to cry out, “A voice from the east, a voice from the west, a voice from the four winds, a voice against Jerusalem and the sanctuary, a voice against the bridegroom and the bride, a voice against all the people.” Day and night he went about all the alleys with this cry on his lips. Some of the leading citizens, incensed at these ill-omened words, arrested the fellow and severely chastised him. But he, without a word on his own behalf or for the private ear of those who smote him, only continued his cries as before. Thereupon, the magistrates, supposing, as was indeed the case, that the man was under some supernatural impulse, brought him before the Roman governor; there, although flayed to the bone with scourges, he neither sued for mercy nor shed a tear, but, merely introducing the most mournful of variations into his utterances, responded to each lashing with “Woe to Jerusalem!” When Albinus, the governor, asked him who and whence he was and why he uttered these cries, he answered him never a word, but unceasingly reiterated his dirge over the city, until Albinus pronounced him a maniac and let him go. During the whole period up to the outbreak of war he neither approached nor was seen talking to any of the citizens, but daily, like a prayer that he had conned, repeated his lament, “Woe to Jerusalem!” He neither cursed any of those who beat him from day to day, nor blessed those who offered him food: to all men that melancholy presage was his one reply. His cries were loudest at the festivals. So for seven years and five months he continued his wail, his voice never flagging nor his strength exhausted, until in the siege, having seen his presage verified, he found his rest. For, while going his round and shouting in piercing tones from the wall, “Woe once more to the city and to the people and to the temple,” as he added a last word, “and woe to me also,” a stone hurled from the ballista struck and killed him on the spot. So with those ominous words still upon his lips he passed away.
Their are 18 parallels to the gospel story. Same order:
Both were named Jesus
Both were peasants
Both appeared in Jerusalem during holy days
Both predicted destruction of the temple
Both predicted destruction of the walls
Both predicted destruction of the population
Both predicted destruction of themselves
Both created a temple disturbance
Both were arrested by the Jewish leaders
Both were beaten by the Jews
Both were brought before the Roman governor by the Jewish leaders
Both were scourged by order of the Roman governor
Both resisted the urge to ask for clemency
Both remained silent when the Roman governor asked their identity
Both remained silent when accused of crimes
Both were thought to be not guilty by the Roman governor
Both were thought to be motivated by some supernatural impulse
Both were ultimately killed by the Romans
Both had their last words recorded lamenting their situation.
So here is one of those “written fragments” which inspired the gospel writers. To argue otherwise, that this was not simply a transposition of one story to another, would strain credulity. But if the gospel writers felt free to transpose an unrelated story into their own, how can their narratives be accorded the status of actual history. On the other hand, if Paul’s teachings were being illustrated through “biographical” narrative, the details would need to be supplied; in the case of the gospels, we can see that the details came from OT verses, Josephus, and not yet discussed here, Homer’s Odyssey. The gospels were a literary device following the popular format of the time, the traveling epic.