But if all prophesy, and there come in one that believeth not, or one unlearned, he is convinced of all, he is judged of all:
All - one by one (1 Corinthians 14:31).
Prophesy - speak by the Spirit intelligibly; not in unintelligible tongues.
One - singular, implying that conviction by all would be produced on anyone who might happen, to enter. In 1 Corinthians 14:23 the plural, "unlearned" or "unbelievers," implying that however many there be, not one will profit by the tongues; yea, their being many would confirm them in rejecting the sign, as many unbelievers together strengthen one another in unbelief: individuals are more easily won.
He - the "one that believeth not."
Convinced - convicted in conscience (John 16:8-9). Judged - his secret character is "discerned," namely, the "one unlearned" (cf. 1 Corinthians 2:15), who, however unskilled in other tongues, can understand the language that speaks to his heart.