Main point summary
Paul rebuked Peter because he tried to force Gentiles to follow the Jewish law, thus acting contrary to the truth of justification by faith, which glorifies the grace of God and carries out the purpose of Christ's death.
But e when Cephas came to Antioch,
I opposed him f to his face,
because he stood condemned.
For before certain men came from James,
g he was eating with the Gentiles;
but when they came
he drew back and separated himself,
fearing h the circumcision party. 1
And the rest of the Jews acted hypocritically along with him,
so that even Barnabas was led astray by their hypocrisy.
But when I saw that their i conduct was not in step with j the truth of the gospel,
I said to Cephas k before them all,
“If you... live like a Gentile and not like a Jew,
...though a Jew, ...
how can you force the Gentiles to live like Jews?”
We ourselves are Jews by birth
and not m Gentile sinners;
yet we know
that n a person is not justified 1
by works of the law
o but through faith in Jesus Christ,
so we also have believed in Christ Jesus,
in order to be justified
by faith in Christ
and not by works of the law,
p because ... no one will be justified.
...by works of the law...
But if, in our endeavor to be justified in Christ, we too were found q to be sinners,
is Christ then a servant of sin?
For if I rebuild what I tore down,
I prove myself to be a transgressor.
For through the law I r died to the law,
so that I might s live to God.
I have been t crucified with Christ.
It is no longer I who live,
but Christ who lives u in me.
And the life I now live in the flesh I live
by faith in the Son of God,
v who loved me
and w gave himself for me.
I do not nullify the grace of God,
for x if righteousness 1 were through the law,
y then Christ died for no purpose.
Paul rebuked Peter because he tried to force Gentiles to follow the Jewish law, thus acting contrary to the truth of the gospel.
Even though the apostles were Jewish, they believed in Jesus so that they would be justified by faith, not works.
The result of justification by faith is not a promotion of sin, but a glorifying of the grace of God and carrying out the purpose of Christ's death.
Paul refused to promote the Jewish law, because he died to the law in Christ, thus glorifying God's grace and carrying out the purpose of Christ's death.
"So" = "therefore"
Paul is saying, "No; on the contrary , I myself would be a servant of sin!"
Paul is saying, "But I refuse to rebuild and promote the law because ..."
The positive restatement of this in v. 19-20 is that Paul promotes the grace of God, and carries out the purpose of Jesus' death - which the law actually opposes and nullifies !