1 Corinthians 14:2

And these signs shall follow them that believe; In my name shall they cast out devils; they shall speak with new tongues;

For they heard them speak with tongues, and magnify God. Then answered Peter,

And when Paul had laid his hands upon them, the Holy Ghost came on them; and they spake with tongues, and prophesied.

And they were all filled with the Holy Ghost, and began to speak with other tongues, as the Spirit gave them utterance. And there were dwelling at Jerusalem Jews, devout men, out of every nation under heaven. Now when this was noised abroad, the multitude came together, and were confounded, because that every man heard them speak in his own language. And they were all amazed and marvelled, saying one to another, Behold, are not all these which speak Galileans? And how hear we every man in our own tongue, wherein we were born? Parthians, and Medes, and Elamites, and the dwellers in Mesopotamia, and in Judea, and Cappadocia, in Pontus, and Asia, Phrygia, and Pamphylia, in Egypt, and in the parts of Libya about Cyrene, and strangers of Rome, Jews and proselytes, Cretes and Arabians, we do hear them speak in our tongues the wonderful works of God.

And though I have the gift of prophecy, and understand all mysteries, and all knowledge; and though I have all faith, so that I could remove mountains, and have not charity, I am nothing.

So likewise ye, except ye utter by the tongue words easy to be understood, how shall it be known what is spoken? for ye shall speak into the air. There are, it may be, so many kinds of voices in the world, and none of them is without signification. Therefore if I know not the meaning of the voice, I shall be unto him that speaketh a barbarian, and he that speaketh shall be a barbarian unto me.

But God hath revealed them unto us by his Spirit: for the Spirit searcheth all things, yea, the deep things of God.

Even the mystery which hath been hid from ages and from generations, but now is made manifest to his saints: To whom God would make known what is the riches of the glory of this mystery among the Gentiles; which is Christ in you, the hope of glory:

How that by revelation he made known unto me the mystery; (as I wrote afore in few words, Whereby, when ye read, ye may understand my knowledge in the mystery of Christ) Which in other ages was not made known unto the sons of men, as it is now revealed unto his holy apostles and prophets by the Spirit; That the Gentiles should be fellowheirs, and of the same body, and partakers of his promise in Christ by the gospel: Whereof I was made a minister, according to the gift of the grace of God given unto me by the effectual working of his power. Unto me, who am less than the least of all saints, is this grace given, that I should preach among the Gentiles the unsearchable riches of Christ; And to make all men see what is the fellowship of the mystery, which from the beginning of the world hath been hid in God, who created all things by Jesus Christ:

I thank my God, I speak with tongues more than ye all: Yet in the church I had rather speak five words with my understanding, that by my voice I might teach others also, than ten thousand words in an unknown tongue. Brethren, be not children in understanding: howbeit in malice be ye children, but in understanding be men. In the law it is written, With men of other tongues and other lips will I speak unto this people; and yet for all that will they not hear me, saith the Lord. Wherefore tongues are for a sign, not to them that believe, but to them that believe not: but prophesying serveth not for them that believe not, but for them which believe. If therefore the whole church be come together into one place, and all speak with tongues, and there come in those that are unlearned, or unbelievers, will they not say that ye are mad?

Behold, I shew you a mystery; We shall not all sleep, but we shall all be changed,

But we speak the wisdom of God in a mystery, even the hidden wisdom, which God ordained before the world unto our glory:

And without controversy great is the mystery of godliness: God was manifest in the flesh, justified in the Spirit, seen of angels, preached unto the Gentiles, believed on in the world, received up into glory.

Holding the mystery of the faith in a pure conscience.

And they that were with me saw indeed the light, and were afraid; but they heard not the voice of him that spake to me.

That their hearts might be comforted, being knit together in love, and unto all riches of the full assurance of understanding, to the acknowledgement of the mystery of God, and of the Father, and of Christ;

The Lord shall bring a nation against thee from far, from the end of the earth, as swift as the eagle flieth; a nation whose tongue thou shalt not understand;

And for me, that utterance may be given unto me, that I may open my mouth boldly, to make known the mystery of the gospel,

Go to, let us go down, and there confound their language, that they may not understand one another’s speech.

And they knew not that Joseph understood them; for he spake unto them by an interpreter.

And he said unto them, Unto you it is given to know the mystery of the kingdom of God: but unto them that are without, all these things are done in parables:

He answered and said unto them, Because it is given unto you to know the mysteries of the kingdom of heaven, but to them it is not given.

My mouth shall speak of wisdom; and the meditation of my heart shall be of understanding. I will incline mine ear to a parable: I will open my dark saying upon the harp.

I will open my mouth in a parable: I will utter dark sayings of old:

But in the days of the voice of the seventh angel, when he shall begin to sound, the mystery of God should be finished, as he hath declared to his servants the prophets.

Now to him that is of power to stablish you according to my gospel, and the preaching of Jesus Christ, according to the revelation of the mystery, which was kept secret since the world began,

Else when thou shalt bless with the spirit, how shall he that occupieth the room of the unlearned say Amen at thy giving of thanks, seeing he understandeth not what thou sayest?

If any man speak in an unknown tongue, let it be by two, or at the most by three, and that by course; and let one interpret. But if there be no interpreter, let him keep silence in the church; and let him speak to himself, and to God.

Then said Eliakim the son of Hilkiah, and Shebna, and Joah, unto Rab–shakeh, Speak, I pray thee, to thy servants in the Syrian language; for we understand it: and talk not with us in the Jews’ language in the ears of the people that are on the wall.