Paul introduces himself as an apostle sent not by men or through a man, but by Jesus Christ and God the Father, who raised him from the dead. With the brothers who are with him he greets the churches of Galatia, wishes them grace and peace and reminds them that Christ gave himself for our sins to deliver us from the present evil age, according to the will of God. The praise closes with an amen, but something is missing: unlike in his other letters, Paul gives no thanks for his readers.
Instead he voices his astonishment: the Galatians are quickly turning from the one who called them by the grace of Christ to a different gospel, which is really not another gospel but a distortion of the only one. Paul places under a curse anyone, himself or an angel from heaven included, who preaches a gospel other than the one they received, and he repeats it so there is no doubt. He makes clear that he is not seeking human approval, for then he would not be a servant of Christ.
Next he defends the origin of his message: he did not receive it from any man but through a revelation of Jesus Christ. He recalls his former life in Judaism, when he violently persecuted the church of God and advanced beyond many of his own age in zeal. But God, who had set him apart from his mother's womb, was pleased to reveal his Son in him so that he might preach him among the Gentiles. He consulted no one and did not go up to Jerusalem; he went to Arabia and returned to Damascus.
Three years later he went up to Jerusalem to get to know Cephas and stayed with him fifteen days; besides him he saw only James, the Lord's brother. Then he went to the regions of Syria and Cilicia. The churches of Judea did not know him by sight; they only heard that the former persecutor was now preaching the faith he once tried to destroy, and they glorified God because of him.