Peter came from Jerusalem to Antioch. The first thing to note is Peter’s freedom then. He enjoyed fellowship with all the believers, Jews and Gentiles alike. To “eat with the Gentiles” meant to accept them, to put Jews and Gentiles on the same level as one family in Christ.
Raised as an orthodox Jew, Peter had a difficult time learning this lesson. Jesus had taught it while He was with Peter before the Crucifixion (Matt. 15:1–20). The Holy Spirit had reemphasized it when He sent Peter to the home of Cornelius, the Roman centurion (Acts 10). Furthermore, the truth had been accepted and approved by the conference of leaders at Jerusalem (Acts 15). Peter had been one of the key witnesses at that time.
In this final historical incident Paul related how he found it necessary to oppose even Peter, the reputed chief of the apostles, for conduct which threatened to compromise the gospel. The contrast with the previous section is dramatic. Paul had risked his life to carry the Gospel of God’s grace to the regions beyond, and he was not willing for the enemy to rob him or his churches of their liberty in Christ. It was this vigilance that led Paul into another dramatic encounter, this time with the Apostle Peter.