I mentioned in my post on the history of early Christianity that Paul says in 1 Cor 15 that Jesus appeared to “Cephas (κηφας::kefas), and then the twelve” which might imply that Peter and Cephas are two different people. Because according to the gospel narratives, Peter was one of the twelve. Thus Paul should have written “Cephas and the eleven” if Peter and Cephas were indeed the same person.
Galatians 2:6-14 is the only mention of a person named “Peter” (πετρος::petros) in Paul’s letters. Assuming they are the same person, every other instance of this “pillar” Paul uses the name Cephas. Why Paul would out of the blue decide to call Peter “Peter” here instead of his usual “Cephas” has no other explanation other than interpolation.
6απο δε των δοκουντων ειναι τι οποιοι ποτε ησαν ουδεν μοι διαφερει προσωπον [ο] θεος ανθρωπου ου λαμβανει εμοι γαρ οι δοκουντες ουδεν προσανεθεντο
7αλλα τουναντιον ιδοντες οτι πεπιστευμαι το ευαγγελιον της ακροβυστιας καθως πετρος της περιτομης
8ο γαρ ενεργησας πετρω εις αποστολην της περιτομης ενηργησεν και εμοι εις τα εθνη
9και γνοντες την χαριν την δοθεισαν μοι ιακωβος και κηφας και ιωαννης οι δοκουντες στυλοι ειναι δεξιας εδωκαν εμοι και βαρναβα κοινωνιας ινα ημεις εις τα εθνη αυτοι δε εις την περιτομην
10μονον των πτωχων ινα μνημονευωμεν ο και εσπουδασα αυτο τουτο ποιησαι
11οτε δε ηλθεν κηφας εις αντιοχειαν κατα προσωπον αυτω αντεστην οτι κατεγνωσμενος ην
12προ του γαρ ελθειν τινας απο ιακωβου μετα των εθνων συνησθιεν οτε δε ηλθον υπεστελλεν και αφωριζεν εαυτον φοβουμενος τους εκ περιτομης
13και συνυπεκριθησαν αυτω [και] οι λοιποι ιουδαιοι ωστε και βαρναβας συναπηχθη αυτων τη υποκρισει
14αλλ οτε ειδον οτι ουκ ορθοποδουσιν προς την αληθειαν του ευαγγελιου ειπον τω κηφα εμπροσθεν παντων ει συ ιουδαιος υπαρχων εθνικως και ουκ ιουδαικως ζης πως τα εθνη αναγκαζεις ιουδαιζειν
6As for those who seemed to be important—whatever they were makes no difference to me; God does not judge by external appearance—those men added nothing to my message.
7On the contrary, they saw that I had been entrusted with the task of preaching the gospel to the Gentiles, just as Peter had been to the Jews.
8For God, who was at work in the ministry of Peter as an apostle to the Jews, was also at work in my ministry as an apostle to the Gentiles.
9James, Cephas, and John, those reputed to be pillars, gave me and Barnabas the right hand of fellowship when they recognized the grace given to me. They agreed that we should go to the Gentiles, and they to the Jews.
10All they asked was that we should continue to remember the poor, the very thing I was eager to do.
11When Cephas came to Antioch, I opposed him to his face, because he was clearly in the wrong.
12Before certain men came from James, he used to eat with the Gentiles. But when they arrived, he began to draw back and separate himself from the Gentiles because he was afraid of those who belonged to the circumcision group.
13The other Jews joined him in his hypocrisy, so that by their hypocrisy even Barnabas was led astray.
14When I saw that they were not acting in line with the truth of the gospel, I said to Cephas in front of them all, “You are a Jew, yet you live like a Gentile and not like a Jew. How is it, then, that you force Gentiles to follow Jewish customs?”
In the reconstructed version of Marcion’s To the Galatians, Gal 2:7-8 are not in it:
(Gal 2:5) To these not even for an hour we yielded in subjection, That the truth of the gospel might continue with you.
(Gal 2:6) But from those reputed to be something – those of repute conferred nothing to me.
(Gal 2:7) But against them, when they had seen that I was entrusted the gospel of the uncircumcision.
(Gal 2:9) Peter, James and John , who regard themselves pillars, gave to me the right of fellowship: – to me the nations – to them the circumcision
In the Epistle of the Apostles (EoA), the writer gives a list of all of the apostles:
2 We, John, Thomas, Peter, Andrew, James, Philip, Bartholomew, Matthew, Nathanael, Judas Zelotes, and Cephas, write unto the churches of the east and the west, of the north and the south declaring and imparting unto you that which concerneth our Lord Jesus Christ
The only question that remains is why the interpolation? The only other instance of “Cephas” in the entire NT besides 1 Corinthians and Galatians is at John 1:42, who deliberately joins the two. However, the EoA uses the same motiffs as the gospel of John (disciples poking holes in Jesus’ wounds) so they might have been using that gospel as a source. If so, how could they separate Cephas and Peter?
The interpolation doesn’t add or subtract anything to Paul’s rant here, so the only purpose must be the same purpose as John 1:42 – joining the name Cephas and Peter into one person. Nowhere else does Paul mention that a “Peter” is a pillar of this Jesus movement. Maybe this version of Gal 2:7-8 is the same person who wrote John 1:42.
Edit: Or maybe the interpolation does detract from the rant a bit. Reading this section without the interpolation, Paul obviously has no love for the “so-called” pillars. Which follows the theme of 2:6 where he obviously said that their apparent leadership had no effect on his message, only that he remember the poor (which he did). Using the word δοκουντες::dokountes to describe them (“so-called”) makes sense of how he had no qualms about rebuking Cephas to his face later on in the letter. The interpolated passage softens the vitrol of Paul’s disdain for these pillars… which makes it seem slightly anti-Marcionite.