John Calvin Commentary Galatians 4:15

"Where then is that gratulation of yourselves? for I bear you witness, that, if possible, ye would have plucked out your eyes and given them to me." — Galatians 4:15 (ASV)

Where is there your blessedness? Paul had made them happy, and he intimates that the devout affection with which they formerly regarded him was an expression of their happiness. But now, by allowing themselves to be deprived of the services of him to whom they should have attributed whatever knowledge they had of Christ, they showed that they were unhappy. This hint was intended to produce keen reflection. “What? Will all this be lost? Will you forfeit all the advantage of having once heard Christ speaking by my lips? Will the foundation in the faith which you received from me be to no purpose? Will your falling away now destroy the glory of your obedience in the presence of God?” In short, by despising the pure doctrine which they had embraced, they throw away, of their own accord, the blessedness which they had obtained, and draw down upon themselves the destruction in which their unhappy career must terminate.

For I bear you record. It is not enough for pastors to be respected if they are not also loved, for both are necessary for the doctrine they preach to be fully relished; and both, the apostle declares, had existed among the Galatians. He had already spoken of their respect for him, and he now speaks of their love. To be willing to pluck out their own eyes, if it had been necessary, was evidence of very extraordinary love, stronger than the willingness to part with life.