John Calvin Commentary 1 Corinthians 14:25

"the secrets of his heart are made manifest; and so he will fall down on his face and worship God, declaring that God is among you indeed." — 1 Corinthians 14:25 (ASV)

Falling down on his face, he will worship. For it is only the knowledge of God that can bring down the pride of the flesh. To that, prophecy brings us. Hence, it is its proper effect and nature to bring people down from their loftiness, so that they may, with prostrate homage, render worship to God.

To many, however, prophecy is also of no benefit—indeed, they are made worse by what they hear. Nor was it even Paul’s intention to ascribe this effect to prophecy, as if this effect were always its result. He simply intended to show how much advantage is derived from it, and what its purpose is. It is therefore a singular commendation that it compels from unbelievers this confession: that God is present with His people, and that His majesty shines forth in the midst of their assembly.