What happens if everyone in the church meeting does their own thing all at once?
If everyone in the church meeting does their own thing all at once—speaking in various languages or bringing separate psalms, doctrines, tongues, revelations, and interpretations—the result is confusion. Unbelievers or unlearned visitors will conclude the participants are mad, even maniacs. Paul therefore commands that all things be done decently and unto edification.
Les teaches that in this passage, Paul describes what happens when the whole church comes together and everyone speaks with various languages at once. An unbeliever or unlearned person entering would hear a conglomeration of languages and conclude they are mad—the Greek root of 'mad' is 'maniac.' But if all prophesy, the unbeliever is convinced and judged, the secrets of his heart are made manifest, and he worships God. Verse 26 asks what you have if everyone brings a psalm, doctrine, tongue, revelation, and interpretation all at once: confusion. Therefore, Paul says all things should be done unto edification, and verse 40 says everything should be done decently.
How is it then, brethren? when ye come together, every one of you hath a psalm, hath a doctrine, hath a tongue, hath a revelation, hath an interpretation. Let all things be done unto edifying.