John Calvin Commentary 2 Corinthians 11:5

"For I reckon that I am not a whit behind the very chiefest apostles." — 2 Corinthians 11:5 (ASV)

For I reckon that I am. He now convicts them of ingratitude by removing the only thing that could serve as an excuse for them, for he shows that he is on a level, even with the chief of the Apostles. The Corinthians, therefore, were ungrateful in not esteeming him more highly, after having found him, by experience, to be such; while, on the other hand, the authority that was justly due to him, they transferred to persons of no value.

For the sake of modesty, however, he says that he reckons so, while the thing was known and manifest to all. His meaning, however, is that God had honored his Apostleship with no less distinguished marks of favor than that of John or Peter.

Now the man that despises the gifts of God, which he himself recognizes, cannot clear himself from the charge of being spiteful and ungrateful. Hence, wherever you see the gifts of God, you must there reverence God himself: I mean, that every one is worthy of honor, insofar as he is distinguished by graces received from God, and especially if any advantage has redounded to you from them.