Albert Barnes Commentary 2 Corinthians 11:31

"The God and Father of the Lord Jesus, he who is blessed for evermore knoweth that I lie not." — 2 Corinthians 11:31 (ASV)

The God and Father, and so on. Paul was accustomed to make solemn appeals to God for the truth of what he said, especially when it was likely to be called in question. See 2 Corinthians 11:10. Compare to Romans 9:1. The solemn appeal which he here makes to God is made in view of what he had just said of his sufferings, not of what follows—for there was nothing in the occurrence at Damascus that demanded so solemn an appeal to God.

The reason for this solemn declaration is, probably, that the transactions to which he had referred were known to only a few, and perhaps not all of them even to his best friends; that his trials and calamities had been so numerous and extraordinary that his enemies would say they were improbable, and that all this had been the mere fruit of exaggeration; and since he had no witnesses to appeal to for the truth of what he said, he makes a solemn appeal to the ever-blessed God.

This appeal is made with great reverence. It is not rash or bold, and is by no means irreverent or profane; he appeals to God as the Father of the Redeemer whom he so much venerated and loved, and as himself blessed for evermore. If all appeals to God were made on occasions as important as this, and with the same profound veneration and reverence, such appeals would never be improper, and we should never be shocked, as we often are now, when men appeal to God. This passage proves that an appeal to God on great occasions is not improper; it also proves that it should be done with profound veneration.