1 Corinthians 14:23

If therefore the whole church
The whole congregation of believers incorporated together in a Gospel church state, consisting of its officers and private members; the church at Corinth is particularly designed:

be come together in one place;
to worship God, to pray unto him, sing his praise, preach and hear the word, as were usually done. Hence may be observed the custom of the primitive churches to meet together, in some certain place, for divine worship; nor did the members of them in common forsake the assembling of themselves together on that account, though it was the evil practice of some of them; the whole church, all the members of it, met together: and it may be seen from hence, that the church, and the place where it met, are two different things:

and all speak with tongues;
divers tongues, languages not understood; meaning, not that all that came together spoke with tongues; but that as many as did speak, should they speak with such, and without an interpreter.

And there come in those that are unlearned, or unbelievers;
either private Christians, who, though they have learned Christ, and understand the doctrines of the Gospel, yet are ignorant of languages; or rather the same persons with unbelievers, Heathens that have no knowledge of Christ, nor faith in him, and who also understood no other language but the Greek: if any such persons should come into the place where the church was met together, and should hear him or them that spoke, speak in a language they understood not, and which they were very well assured was equally unknown to the whole congregation, and so could be of no service to them:

will they not say ye are mad?
act like men in a frenzy, that have not the use of their reason; since speaking in a strange language to a congregation that know not one word of what is said, is speaking to the air, and to no profit at all to them that hear; and who but a madman would do this? The apostle here argues from the scandal and contempt that would be poured upon them by such a practice; and the rather he mentions this, because it seems as if their governing view was the glory and applause of men, in which, he suggests, they would be sadly disappointed.