Paul’s letter to the Galatians, chapter 2, verses 11-14
11 When Cephas came to Antioch, I opposed him to his face, because he stood condemned. 12 For before certain men came from James, he used to eat with the Gentiles. But when they arrived, he began to draw back and separate himself from the Gentiles because he was afraid of those who belonged to the circumcision group. 13 The other Jews joined him in his hypocrisy, so that by their hypocrisy even Barnabas was led astray. 14 When I saw that they were not acting in line with the truth of the gospel, I said to Cephas in front of them all, “You are a Jew, yet you live like a Gentile and not like a Jew. How is it, then, that you force Gentiles to follow Jewish customs?
Muslims sometimes come forward with the Gospel of Barnabas. Supposedly expropriated by church leaders. Matthew till John would then be adjustments to the heresies of Paul, who did not agree with Barnabas. After all, they disagreed and parted (Acts 15:39). In Antioch they clashed as well. The book of Barnabas is a medieval persiflage of the hand of someone who had become a Muslim. Jesus will witness against them who call him “God’s Son’. Judas is crucified. And Jesus announces the coming Muhammad, the “seal of the prophets”, to Barnabas.
In fact, there never is a difference in doctrine between Paul and Barnabas. They quarrel over Barnabas’ cousin John Marc. Not lasting: later they travel to Jerusalem together (Gal. 2:1). Also in Antioch there was no confrontation about the content of, say, circumcision. Paul was vexed by Peter’s and Barnabas’s dealing with newcomers. There were integration problems. Jews missionary Peter and even gentiles missionary Barnabas gave in to the pressure of Jerusalem Christians who did not accept “foreign folk” as full-fledged church members. They let down Christians from gentile background: “own people first”.
Paul backed the gentile converts. He needed to openly distance himself from the hypocrite lifestyle – not the teachings – of his colleagues.
To sing: O Church Arise, verse 2
Our call to war, to love the captive soul,
But to rage against the captor;
And with the sword that makes the wounded whole
We will fight with faith and valor.
When faced with trials on ev’ry side,
We know the outcome is secure,
And Christ will have the prize for which He died—
An inheritance of nations.