A.T. Robertson Commentary 1 Corinthians 14:23

"If therefore the whole church be assembled together and all speak with tongues, and there come in men unlearned or unbelieving, will they not say that ye are mad?" — 1 Corinthians 14:23 (ASV)

Will they not say that ye are mad? (ουκ ερουσιν οτ μαινεσθε?). These unbelievers unacquainted (ιδιωτα) with Christianity will say that the Christians are raving mad (26:24). They will seem like a congregation of lunatics.