Paul desires most of all that he could see evidence that the things he was saying had affected them for good. For then he would no longer have to keep up this tone of rebuke and correction.
The only appropriate response to Paul’s expression of doubt is for the Galatians to be horrified at the thought that he could doubt their state, and to admit that it is true that they have given him just cause for concern. They must realise the seriousness of their departure from the gospel, and strive to end their foolishness and return to the grace of God in Christ Jesus. Sometimes the pastor must use shock in his effort to wake a soul from their sleep-walk before they step over some precipice of destruction. Paul was genuinely in doubt about their salvation because he had not been given privileged information about the elect status of every individual; he had to work as any pastor would by reading the signs of life in the conduct of each professing Christian.