John Calvin Commentary 1 Corinthians 3:21

"Wherefore let no one glory in men. For all things are yours;" — 1 Corinthians 3:21 (ASV)

Therefore let no man glory in men. As there is nothing more vain than man, how little security there is in leaning upon a fleeting shadow! Therefore, he correctly infers from the preceding statement that we must not glory in men, since the Lord thus universally takes away from mankind every basis for glorying.

At the same time, this inference depends on the whole of the preceding doctrine, as will become clear soon. For since we belong to Christ alone, he teaches us with good reason that any supremacy of man which impairs the glory of Christ involves sacrilege.