Galatians 2 tells the story of the argument between Paul and Peter. Peter started bringing legalism to the Gentiles, while Paul taught Grace.
When Cephas (Simon Peter), came to Antioch, Paul met him face to face. Paul said that Peter stood condemned.
While Peter was eating with the Gentiles, men of the Jewish circumcision party came from James to visit. When they arrived, Peter drew back from the Gentiles and separated himself, fearing the circumcision party.
When Peter did this, the rest of the Jews did the same. Paul said that they acted hypocritically, to the extent that even Barnabas was led astray by their hypocrisy.
Paul said that their conduct was not in line with the Gospel of Jesus Christ. Though Jews, they were eating with the Gentiles, which was against the law. Yet when the circumcision party grew in number, they tried to force the law upon the Gentiles. Paul asked them, "If you, though a Jew, live like a Gentile and not a Jew, how can you force the Gentiles to live like Jews?"
They were Jews by birth, and not Gentile sinners. Yet, though Jews, they knew the Gospel of Jesus Christ. A person is not justified by the way they live their lives according to the law; they are justified by faith in Jesus Christ.
Paul said that he believed in Jesus Christ, so that he could be justified by faith instead of the rules and regulations under the law. Through the works of the law, not a single person will be justified.
"But if we are found sinners in our attempt to be justified in Christ", Paul asked, does that make Christ a servant of sin? Certainly not!"
Paul said that if he tried to rebuild what he tore down, as Christ rebuilt the covenant after tearing down the covenant of the law, Paul would be a transgressor. Through the law he died to the law so that he could live in God.
Paul said that he now had been crucified with Christ. It is no longer the man, Paul, who lived, but Christ who lived in him. The life he now lived is not in the flesh, he lived by faith in Jesus Christ. He lived by the Son of God who loved him and gave Himself for all.
Paul said that if we were righteous by the way we lived according to the rules and regulations of the law, then we have nullified the Grace of God and Christ died for no purpose!
As Christians, we should ask ourselves: Do we nullify the Grace of God by trying to uphold the rules of the law to gain righteousness? Have we made Christ die in vain for our souls? When others claim their righteousness through their holy ways, do we join in their hypocrisy? If see others who forbid themselves entertainment or modern clothing for their righteousness, do we bathe ourselves in their folly by imposing this upon ourselves and others? Do we have the same message as Paul, or have we followed Peter's mistake?