In the Apostle's opinion, believers will benefit from forthtelling, whereas unbelievers will profit from the tongues provided that they are interpreted. He says: “Therefore tongues are for a sign, not to those who believe but to unbelievers; but prophesying is not for unbelievers but for those who believe” (v.22).
Therefore if those who are present in church are believers, what is the benefit of Speaking in tongues, according to the Apostle's teaching?