Galatians is Paul's angriest surviving letter, and its opening announces the tone: where every other Pauline letter opens with thanksgiving for its recipients, Galatians skips straight to reproach, "I am astonished that you are so quickly deserting the one who called you." The dispute is concrete: teachers, whom Paul calls agitators, had persuaded Gentile converts in Galatia that faith in Christ was not enough, that they also needed to be circumcised and keep the Jewish law to belong fully to God's people. Paul answers with his own testimony, recounting his conversion and his confrontation with Peter at Antioch over table fellowship with Gentiles, before mounting a scriptural argument from Abraham, who was counted righteous by faith before the law existed at all.
The letter's most quoted line, "there is no longer Jew or Greek, slave or free, male and female, for you are all one in Christ Jesus," appears here rather than in Romans, offered as evidence that the law's distinctions no longer determine who belongs to God's family. Paul closes with a stark image of freedom against slavery, urging the Galatians to "stand firm" rather than submit again to what he calls a yoke, and ends, unusually, by noting he is writing the final lines in his own large handwriting rather than dictating to a scribe.