Normally Paul thanked God for some quality of the addressees immediately after the salutation. However, instead of doing so in the letter to the Galatians, he rebuked them.
No Other Gospel
6 I am astonished that you are so quickly deserting him who called you in the grace of Christ and are turning to a different gospel–7 not that there is another one, but there are some who trouble you and want to distort the gospel of Christ. (ESV; all Biblical quotations are from the ESV)
If the letter was Paul’s first one, as I claimed in Galatians — the Magna Carta of Christian Liberty, possibly he didn’t develop his practice of expressing thanks after the salutation until later. However, since expressing thanks after the salutation was a common form in Greek letter writing, more likely the substitution reflects Paul’s concern over the Galatians’ listening to visitors who had told them that they to be circumcised and obey the Mosaic law, in addition to believing in Jesus Christ, to be saved. As I observed in my two earlier articles on Paul’s letter to the Galatians, we call people who taught this Judaizers.
Paul was genuinely surprised and upset by the Galatians’ turning from the gospel that he had preached to them to the teaching of the Judaizers so soon after they had accepted the gospel that he had preached to them. In Paul’s opinion, the teaching of the Judaizers was too different from the gospel which he had preached to them to be called “gospel.” Indeed, according to him, nobody would call it a “gospel” except troublemakers wanting to pervert the true gospel. Thus he viewed the Galatians as being on the verge of abandoning “him who called [them] in the grace of Christ,” God. (It is possible that “one” refers to Paul himself or Christ, but elsewhere in Galatians and Paul’s other letters he refers to God as the one who calls and so it is more likely that “one” refers to God.)
Let Him Be Accursed
8 But even if we or an angel from heaven should preach to you a gospel contrary to the one we preached to you, let him be accursed. 9 As we have said before, so now I say again: If anyone is preaching to you a gospel contrary to the one you received, let him be accursed.
In these verses, Paul invokes God’s eternal condemnation upon anybody, even an angel or Paul himself, who preaches a message conflicting with the gospel that Barnabas and he had preached to the Galatians and that they had accepted.
What was the gospel that Paul preached and that the Galatians accepted? Elsewhere he describes it as the good news
3 concerning [God’s] Son, who was descended from David according to the flesh 4 and was declared to be the Son of God in power according to the Spirit of holiness by his resurrection from the dead, Jesus Christ our Lord (Romans 1:3-4)
3 that Christ died for our sins in accordance with the Scriptures, 4 that he was buried, that he was raised on the third day in accordance with the Scriptures, 5 and that he appeared (1 Corinthians 15:3-5)
However, in light of what follows, Paul primarily has the principle of justification by faith in mind.
Man or God?
10 For am I now seeking the approval of man, or of God? Or am I trying to please man? If I were still trying to please man, I would not be a servant of Christ.
Apparently, the visitors had told the Galatians that Paul’s not requiring them to be circumcised and obey the Mosaic law showed that he was more interested in pleasing men than in pleasing God. If Paul wrote his letter to the Galatians later than I think he did, the visitors may have cited in support of their claim Paul’s having Timothy circumcised (Acts 16:3) although refusing to have Titus circumcised (Galatians 2:3). (I think that he wrote it between his first and second missionary journeys to the churches which Barnabas and he had founded in the Roman province of Galatia on Paul’s first missionary journey, but many scholars think that he wrote it during his third missionary journey to ethnic Galatia. See [Galatians — the Magna Carta of Christian Liberty].)
Paul argues that if this were true he wouldn’t be serving as a slave of Christ. Instead he would, in the words of John Chrysostom, “still consort with the Jews, still persecute the church.” Chrysostom continues:
I [Paul] who have cast off my country altogether, my companions, my friends, my kindred, and all my reputation, and taken in exchange for these, persecution, enmity, strife, and daily-impending death, have given a signal proof that I speak not from human applause. This he says, being about to narrate his former life, and sudden conversion, and to demonstrate clearly that it was sincere. (Homilies on Galatians … Philemon, A Select Library of the Nicene and Post-Nicene Fathers of the Christian Church, ed. Philip Schaff [Grand Rapids, Michigan: William B. Eerdmans Publishing Company, 1969 reprint], 9)
We live in an age that emphasizes toleration so much that it has become unacceptable for any group to profess that it is the only way to Heaven. In light of Galatians 1:6-10, how do you think that Paul would respond to this aspect of our age?