1 Corinthians 14: 21. In Torah it is written: With a foreign speech, and in another tongue, will I speak with this people; and even so also they will not hear and obey me, says Master YHWH. 22. Wherefore, tongues are established for a sign, not to the believers, but to them that do not believe. But prophecies are not for those who disbelieve, but for them that believe. (AENT)
1 Peter 4:10 10. And let each of you minister to his associates the gift which he have received from Elohim; as being good stewards of the manifold grace of Elohim. 11. Whoever will speak, let him speak as the Word of Elohim: and whoever will minister, as of the ability that Elohim have given him: so that in all you do, Elohim may be glorified through Y’shua the Mashiyach to whom belongs glory and honor forever and ever. Amen. (AENT
1: Rav Sha’ul/Paul spends a lot of time explaining to the church at Corinth that the most important thing to God is self-sacrificing love to one another, not using selfish religious practices to build themselves up. He gives a long explanation of agape love [1 Corinthians 13], and then applies love to spiritual gifts [1 Corinthians 14]. In a local church of people with all the same language, a gift of tongues could only be used in a selfish manner. Once he got this point established, he made this clear statement: “Therefore tongues are for a sign, not to those who believe but to unbelievers; …” This statement kills the theory that speaking in tongues is for personal use or spiritual edification of the church. Tongues is for one purpose: to minister to the lost unbelievers. This is exactly what YHWH used tongues for in Acts 2. Spiritual gifts are never designed for selfish use; “minister it to one another” is obviously to serve someone else.
1 Corinthians 14: 26. I therefore say (to you) my Brothers, that when you assemble, whoever of you has a psalm, let him speak; and whoever has a doctrine, and whoever has a revelation, and whoever has a tongue, and whoever has an interpretation. Let them all be for edification. 27. And if any speak in a tongue, let two speak or at most, three; and let them speak one by one; and let (some) one interpret. 28. And if there is none to interpret, let him that speaks in a tongue, be silent in the assembly; and let him speak to himself and to Elohim. (AENT)
Have you ever noticed that all the interpretations given in tongues-speaking circles are “secret messages from God,” and normally not words to God? Paul says they are all words to God or men. “…if I pray in a tongue…sing with the spirit…bless with the spirit….”
1 Corinthians 14: 6. And now, my Brothers, if I should come among you and speak to you in tongues, what should I profit you; unless I should speak to you either by revelation, or by knowledge, or by prophecy, or by doctrine? 7. For even inanimate things that emit sound, whether pipe or harp, if they make no distinction between one sound and another, how will it be known what is sung or what is harped? 8. And if the shofar will give an uncertain sound, who will prepare himself for the battle? 9. So likewise if you utter many words in a tongue, and there is no interpretation given, how will it be known what you have said? You will have been as if you spoke into the air. 10. For behold, there are many kinds of tongues in the world; and there is not one of them without meaning. 11. But if I do not know the import of the sound, I will be a barbarian to him that speaks, and the speaker will be a barbarian to me. (AENT)
1 Corinthians 14: 12. So also you, since you are searching for the gifts of the Spirit for the edification of the assembly, you seek to excel. 13. And let him that speaks in a tongue, pray that he may interpret. 14. For if I should pray in a tongue, my spirit prays, but my (spiritual) understanding  is without fruits. 15. What then will I do? I will pray with my spirit, and will pray with my understanding; and I will sing with my spirit, and will sing with my understanding. 16. Otherwise, if you bless in the spirit, how will he that fill the place of one unlearned, say Amen on your giving thanks; for he does not know what you say? 17. You bless, indeed, very well; but your neighbor is not edified. 18. I thank Elohim that I speak with tongues more than all of you. 19. But in the assembly, I would rather speak five words with my (spiritual) understanding, that I might instruct others, than a myriad of words in a tongue. (AENT)
FOOTNOTE: Derived from da’at, this word represents a kind of heavenly understanding coming out through prayer as opposed to earthly knowledge.
There is no evidence or statement given in the Scriptures for the commonly practiced private prayer language theory. No secret angelic unknown language either! Chapter 14:10 makes it clear Paul is thinking of regular human languages. Paul stated he spoke in tongues more than all the believers in the Corinthian church. But, not in a gathering, and not in private because he is the one who said it was to be used for a sign to the lost. The only way he could have spoken “with tongues more than you all” as a sign to the lost would be while he traveled the world preaching in the tongues of the lost people that lived all over the Roman empire. Again this would be a sign to the unbelievers matching the historical experience of Pentecost.
In a local assembly such as the church of Corinth illustrates, when believers misuse a spiritual gift, it only brings division into the body and confusion to unsaved guests who speak the same language. “23. If therefore the whole assembly gathers, and they all speak with tongues, and there come in unlearned persons, or those that disbelieve, will they not say: These people are crazy?  ” [14:23]
FOOTNOTE: In other words, “charismatic” manifestations are not to become such a focal point of identity in the fellowship that they become a stumbling block to those entering the Malchut (Kingdom of) Elohim.