John Calvin Commentary Ephesians 3:7

"whereof I was made a minister, according to the gift of that grace of God which was given me according to the working of his power." — Ephesians 3:7 (ASV)

Of which I was made a minister. Having declared the gospel to be the instrument employed in communicating grace to the Gentiles, he now adds that he was made a minister of the Gospel, and thus applies to himself the general statements that had been made. But, to avoid claiming for himself more than is proper, he affirms that it is the gift of the grace of God, and that this gift was an exhibition of divine power.

As if he had said, “Do not inquire what I have deserved, for in the free exercise of kindness, the Lord made me an apostle of the Gentiles, not for any excellence of mine, but by his own grace. Do not inquire what I formerly was, for it is the Lord’s prerogative to ‘exalt them of low degree.’” (Luke 1:52). To produce something great out of nothing shows the effectual working of his power.