John Calvin Commentary 1 Corinthians 8:2

"If any man thinketh that he knoweth anything, he knoweth not yet as he ought to know;" — 1 Corinthians 8:2 (ASV)

And if any man thinketh—that man thinketh that he knoweth something, who is delighted with the opinion he holds of his own knowledge and despises others, as if he were far above them.

For Paul does not condemn knowledge here, but rather the ambition and haughtiness that ungodly men acquire from it. Otherwise, he does not urge us to be skeptical, so that we are always hesitating and remaining in doubt. Nor does he approve of a false and counterfeit modesty, as if it were good to think we are ignorant of what we actually know.

Therefore, that man who thinketh that he knoweth something—or, in other words, who is insolent from an empty notion of his own knowledge, so that he prefers himself to others and is self-conceited—he knoweth nothing yet as he ought to know.

For the beginning of all true knowledge is acquaintance with God, which produces humility and submission in us; indeed, it prostrates us entirely instead of elating us. But where pride is, there is ignorance of God—a beautiful passage! If only everyone understood it correctly, so as to properly understand the rule of right knowledge!