You said Paul claims Peter should be accursed. Paul is telling about what he did regarding Peter and his false gospel. Paul said after it let them be accursed. That is after Acts 15 that circumcision accepts Paul's gospel of faith alone.
Paul rebuked Peter, not for false doctrine (what he
taught) but for hypocrisy:
behaving inconsistently with what he taught. The Lord had already corrected Peter's views about the Gentiles' status in Acts 10.
And he (Peter) said to them, “You yourselves know how
unlawful it is for a Jew to associate with or to visit anyone of another nation, but
God has shown me that I
should not call any person common or unclean (
Acts 10:28).
Since there is no record of Peter teaching anything contrary to this is no basis for your claim that he taught false doctrine. However, after proclaiming publicly that that Jews and Gentiles were both sanctified and that there was no reason why they should not be in fellowship Peter changed his
behavior when a group of "important" Jews showed up. This was a matter not of doctrine but of
hypocrisy.
Paul's comment to Peter was as follows:
But when I saw that
they walked not uprightly according to the truth of the
gospel, I said unto Peter before them all, If thou, being a Jew,
livest after the manner of Gentiles, and
not as do the Jews, why compellest thou the Gentiles to live as do the Jews? (
Galatians 2:14)
The HCSB puts it this way
But when I saw that they were
deviating from the truth of the gospel...(
Galatians 2:14 HCSB)
1. One thing Paul says is that
Peter personally did not live the lifestyle of an observant Jew. What would this involve except such practices as: eating kosher, keeping temple ordinances, teaching circumcision and
steering clear of Gentiles?
2. Paul also says that Peter "
lived like a Gentile." It does not sound like Peter lived like a Jew in accordance with some special "Jewish (or Kingdom) Gospel"
3. However, when the Jews came Peter, fearing their disapproval, returned to the Jewish habits of life and separated himself from the Gentiles. (The Jewish community in those days exerted a lot of pressure on individual Jews to conform to group standards).
4. According to Paul,
before the arrival of the Jewish party, Peter did not "
compel" (or command) the Gentile believers to adopt a Jewish lifestyle...therefore he cannot be accused of teaching the false doctrine of the Judaeizers which posited that one could be saved through the performance of meritorious works (i.e., keeping the Jewish custom and ceremonial law).
5. In order for Paul to rebuke Peter at all they both would have needed to share a belief in a
common standard of behavior. If Peter were obligated to follow different standards embedded in a separate "Jewish Gospel" then Paul would have rebuked him for acting like a Gentile BEFORE the Jews arrived not for acting like a Jew AFTERwards.
6. In this verse, a
single standard is presented:
THE truth of
THE Gospel. One Gospel is presented that was apparently believed by both apostles. Paul's rebuke is predicated on the fact that they
both held to this common teaching Peter's
BEHAVIOR not his
DOCTRINE was inconsistent with THE gospel.
