What kind of power did Paul's Gospel have?
Paul's Gospel had transforming power. It brought pagan Galatians under its influence and produced a deep bond of affection for Paul. They loved him despite his physical inadequacies, so great was the transforming power of the Gospel he preached. This power was evident in their love for him.
Les explains that Paul's Gospel carried transforming power, and the pagan Galatians who came under it developed a deep bond of affection for Paul. They loved him in spite of his physical inadequacies, which Les suggests included an eye problem. They would have given their healthy eyes to replace his sickly ones because of their love for him. Les also reminds us that Galatians is Paul proving we are not under the Law but under Grace.
Where is then the blessedness ye spake of? for I bear you record, that, if it had been possible, ye would have plucked out your own eyes, and have given them to me.