[The audio for this week’s evening service is available at Sermon.net, as is a PDF file of the notes for the service. You should be able to download the audio directly with this link, if you prefer (right-click, save link as….)]
Paul is clear that there is only one Gospel and this gospel is the one that he has already preached to them. Ben Witherington makes two important observations here (Galatians, 80). First, Paul is saying that he has authority to say what the Gospel is, or is not. The Gospel he preached is the Gospel, what the opponents are preaching is “not a gospel.” It is not a variation on the gospel, it is not another view on how the gospel should be presented, nor is it a difference of opinion on a minor matter. The opponent’s teaching is simply “not the gospel”!
Second, Paul has the authority to pronounce a curse on those who preaching this “other gospel.” This authority is derived from the fact that he represents God the Father and the Lord Jesus Christ as their apostle (1:1).
Paul is so committed the gospel that he preached in Galatia that he pronounces a curse upon anyone that preaches a different gospel, even if it is an angel from heaven or Paul himself! Paul makes this sweeping statement in verse 8: Even if an angel preaches another gospel, do not believe it! This means that if Paul were to return to Galatia and declare that the Gentiles needed to keep the Law, the churches ought to not believe him.
That Paul should mention “an angel of the Lord” is important. Later in the letter Paul alludes to the Jewish tradition that the Law was given to Moses through the mediation of angels. Paul is saying that even if a new revelation be given in the same way Moses received the Law contradicts this gospel, it must be rejected.
The fact that Barnabas is missing from the introduction is important. Paul is stating that it does not matter who preaches, if he does not agree with the original gospel he ought to be rejected – even if that person is Barnabas! It is possible Paul’s opponents made something out of the fact that Barnabas separated from table fellowship, siding with them. They could say that Barnabas, the apostle from Jerusalem, agrees with them, not Paul!
People in the multi-cultural world of the twenty-first century might be shocked that Paul states unequivocally that the only way to be right with God is the Gospel which he preached. But this is really the point of Galatians – there is but one Gospel, and that Gospel is Christ Crucified on our behalf. For Paul, anything else is “not-a-gospel.”