11 But when Cephas came to Antioch, I opposed him to his face1, because he was condemned. 12 For before certain people came from James2, he used to eat with gentiles; but when they3 came, he began drawing back4 and separating himself from the gentiles fearing those from the circumcised. 13 And the rest of the Jews5 joined him in the play-acting6 so that even Barnabas was lead astray with their play- acting. 14 But when I saw that they did not walk straightforward7 with the truth of the Gospel, I said to Cephas before all of them, “If you, being a Jew, are living like a gentile and not like a Jew, how can you compel the gentiles to live like Jews?”
Paul writes here of a confrontation that he had with Peter. The most astonishing thing about the passage is just how much influence the "certain people from James" had on Peter and on the Jewish Christians in Antioch. Who could have these people been and why did they have so much influence? The secret may lie in Paul's own words; "For before certain people came from James". James had become the leader of the Church in Jerusalem. Did James have a change of heart to what Paul was preaching? Had he been influenced by prominent Jewish converts in Jerusalem? Did he send these people who even caused Peter to "play-act"? It remains a mystery.
1 κατὰ πρόσωπον αὐτῷ ἀντέστην (I opposed him to his face)
In other words, Paul openly spoke against Peter personally.
2 It is very unclear from the text if James sent these “certain people” or that Paul just merely means that they were from James’ church in Jerusalem. The clues may indicate that James sent these people as Paul names him directly.
3 the “certain people” from James.
4 ὑπέστελλεν (began drawing back)
The verb is in the imperfect which normally carries a “continual” aspect. In this case, Peter “started” to draw back and to separate himself from the gentiles.
5 The Jews in Antioch who had been converted.
6 συνυπεκρίθησαν αὐτῷ (joined him in the play-acting)
To pretend to be something that you are not. The verb was also used in ancient times to refer to people who acted on a stage while performing a play.
7 οὐκ ὀρθοποδοῦσιν (they did not walk straightforward)
or, “they did not act rightly”.
Γαλάτας 2·11 Ὅτε δὲ ἦλθεν Κηφᾶς εἰς Ἀντιόχειαν, κατὰ πρόσωπον αὐτῷ ἀντέστην, ὅτι κατεγνωσμένος ἦν. 12 πρὸ τοῦ γὰρ ἐλθεῖν τινας ἀπὸ Ἰακώβου μετὰ τῶν ἐθνῶν συνήσθιεν· ὅτε δὲ ἦλθον, ὑπέστελλεν καὶ ἀφώριζεν ἑαυτὸν φοβούμενος τοὺς ἐκ περιτομῆς. 13 καὶ συνυπεκρίθησαν αὐτῷ [καὶ] οἱ λοιποὶ Ἰουδαῖοι, ὥστε καὶ Βαρναβᾶς συναπήχθη αὐτῶν τῇ ὑποκρίσει. 14 ἀλλ ̓ ὅτε εἶδον ὅτι οὐκ ὀρθοποδοῦσιν πρὸς τὴν ἀλήθειαν τοῦ εὐαγγελίου, εἶπον τῷ Κηφᾷ ἔμπροσθεν πάντων· εἰ σὺ Ἰουδαῖος ὑπάρχων ἐθνικῶς καὶ οὐχὶ Ἰουδαϊκῶς ζῇς, πῶς τὰ ἔθνη ἀναγκάζεις ἰουδαΐζειν;