But when Cephas came to Antioch, I opposed him to his face, because he was wrong.
References for Galatians 2:11
He had been eating with the Gentiles before certain people came from James. But when they came, he began to back out and separate himself, because he was afraid of the people who promoted circumcision.
And the rest of the Jews also joined him in this hypocrisy so that even Barnabas got carried away with them in their hypocrisy.
But when I saw that they weren't acting consistently with the truth of the gospel, I said to Cephas in front of everyone, "If you, though you're a Jew, live like a Gentile and not like a Jew, how can you require the Gentiles to live like Jews?"
We are born Jews—we're not Gentile sinners.
However, we know that a person isn't made righteous by the works of the Law but rather through the faithfulness of Jesus Christ. We ourselves believed in Christ Jesus so that we could be made righteous by the faithfulness of Christ and not by the works of the Law—because no one will be made righteous by the works of the Law.
But if it is discovered that we ourselves are sinners while we are trying to be made righteous in Christ, then is Christ a servant of sin? Absolutely not!
If I rebuild the very things that I tore down, I show that I myself am breaking the Law.
I died to the Law through the Law, so that I could live for God.
I have been crucified with Christ and I no longer live, but Christ lives in me. And the life that I now live in my body, I live by faith, indeed, by the faithfulness of God's Son, who loved me and gave himself for me.
I don't ignore the grace of God, because if we become righteous through the Law, then Christ died for no purpose.