What is the truth that the Galatians were not obeying?
The truth was the gospel that Jesus Christ was crucified, buried, and risen from the dead, and salvation is by faith in Him plus nothing. The Galatians were not obeying it because Judaizers from Jerusalem had deceived them into adding something to Paul’s gospel, teaching faith plus something.
Les explains that the Galatians were being hoodwinked into thinking they had to add to the gospel, which is why Paul hurried to write this letter. Paul asks who has bewitched them and fooled with their thinking; the culprits were Judaizers from Jerusalem. The truth they were not obeying was Jesus Christ crucified, buried, and risen from the dead, plus nothing. They were saying it had to be plus something. Les notes that previously it was faith plus: Old Testament saints were saved by faith, but not faith alone; even in Christ's earthly ministry people had to repent, be baptized, keep the law, and remain under temple worship. But beginning with Paul's gospel, it is faith plus nothing. He recalls a lady in his Macalester class who made a plaque asking 'faith plus nothing?' and observes that 90% of Christendom says it's faith plus.