"The gift of tongues" are prophesied of in the book of Mark chapter 16 verses 17-18:
"These signs will accompany those who have believed: in My name they will cast out demons, they will speak with new tongues; they will pick up serpents, and if they drink any deadly poison, it will not hurt them; they will lay hands on the sick, and they will recover."
The gift of tongues were displayed by the disciples on the night of Pentecost following Jesus ascension after they were delivered by God's Holy Spirit as shown in Acts chapter 2 of the Bible. It was Xenoglossy; a phenomenon in which a person is able to speak a language that he or she could not have acquired by natural means. We know they were speaking in a manner of xenoglossy by how it is recorded in the account:
"And they were all filled with the Holy Spirit and began to speak with other tongues, as the Spirit was giving them utterance. Now there were Jews living in Jerusalem, devout men from every nation under heaven. And when this sound occurred, the crowd came together, and were bewildered because each one of them was hearing them speak in his own language. They were amazed and astonished, saying, "Why, are not all these who are speaking Galileans? "And how is it that we each hear them in our own language to which we were born?"
11-12, "--we hear them in our own tongues speaking of the mighty deeds of God." And they all continued in amazement and great perplexity, saying to one another, "What does this mean?"
They had been filled with the Holy Spirit and received the 'gift of speaking in tongues', that is, speaking in a language that he or she did not know until that moment and could not have acquired by any other means than through an immediate gift from God. Discovering this, even the disciples were beside themselves in amazement.
What other kinds of 'tongues' are there?
There is Glossolalia. This is the term Paul used for what the people of Corinth were doing. It was a ready made Greek word for something that had been going on in other false religions since ancient times. Unknowable utterances from men to God.
What is known about Glossolalia?
The highly respected 1972 study of John P. Kildahl (The Psychology of Speaking in Tongues) concludes that "from a linguistic point of view, religiously inspired glossolalic utterances have the same general characteristics as those that are not religiously inspired." In fact, glossolalia is a "human phenomenon, not limited to Christianity nor even to religious behavior." (Dictionary of Pentecostal and Charismatic Movements by Spittler, P. 340).Felicitas D. Goodman, a psychological anthropologist and linguist, engaged in a study of various English - Spanish - and Mayan-speaking Pentecostal communities in the United States and Mexico. She compared tape recordings of non-Christian rituals from Africa, Borneo, Indonesia and Japan as well. She published her results in 1972 in an extensive monograph (Speaking in Tongues: A Cross-Cultural Study in Glossolalia by Felecitas D. Goodman, University of Chicago Press, 1972).
Goodman concludes that "when all features of glossolalia were taken into consideration--that is, the segmental structure (such as sounds, syllables, phrases) and its suprasegmental elements (namely, rhythm, accent, and especially overall intonation)-- she concluded that there is no distinction in glossolalia between Christians and the followers of non-Christian (pagan) religions. The "association between trance and glossolalia is now accepted by many researchers as a correct assumption," writes Goodman in the prestigious Encyclopedia of Religion (1987).
Goodman also concludes that glossolalia "is, actually, a learned behavior, learned either unawarely or, sometimes consciously." Others have previously pointed out that direct instruction is given on how to "speak in tongues," ie. how to engage in glossolalia.
In fact, it has been found that the "speaking in tongues" practiced in Christian churches and by individual Christians is identical to the chanting language of those who practice voodoo.
This is the glossolalia that the apostle Paul is referring to in 1 Corinthians chapter 14 verse 2.
2 "For one who speaks in a tongue does not speak to men but to God; for no one understands, but in his spirit he speaks mysteries."
For the rest of the chapter, even using the Lord's own words, Paul schools us in xenoglossy - the Lord's tongues - or when, through other strange languages, by the lips of strangers, the Lord says "He" will speak to His people. Biblical 'tongues' are the Lord speaking 'to men', 'through other men'.
It's also important to note that Paul is not introducing a biblical contradiction here by showing 'tongues' as being spoken like those in 14:2, "not to men but to God", and then posting the Lord as stating in verse 21 that they are spoken "God to men". Paul is not introducing a contradiction into scripture but simply contrasting how they are being spoken in Corinth, to the way the Lord's tongues are actually prescribed by the Lord as being spoken. Paul instructs that the 'tongues to God' going on in 14:2 are, actually, supposed to be the 'tongues to the Lord's people' of 14:21, done with a corresponding edifying message in a known language.
It has been said, "tongues are a sign!". I'm sorry, "tongues to God" had been around over a thousand years before Christ, practiced by false religions, and therefore impossible to be regarded by anyone as any sign from the True God. Anyone can do them, whereas, the Lord only performs signs that no one else can do. See His words in the following verse:
John 15 15:24"If I had not done among them the works which no one else did, they would not have sin; but now they have both seen and hated Me and My Father as well."
Xenoglossia is a sign from God to unbelievers; glossolalia is no sign, but merely unknowable human utterances from 'men to God'.
The recorded cases of Glossolalia go back as far as 1100 B.C. If you would care to click on this link, it takes you to an article by someone named Rene Norbergen. I have not tried to confirm all the things he asserts but don't expect a problem doing so. His references are provided.
Regarding the "Gifts of the Spirit" in general. Today all believers have the "gift" of the Spirit - all have equal and impartial access to the Lord who eagerly bends His ear when we raise our prayers and supplications to Him. We as Christians have to be careful not to put ourselves in the uncertain position, when asked by unbelievers about the available healing powers of God, of pointing to individuals we claim are given special Spiritual healing powers. There were once those disciples who healed everyone that was brought to them. Those have ceased while healing and miracles still go on today through prayer and supplication according to the Lord's will. Today, we freely go to His waiting ear in faith and thanksgiving, and ask that healing be done, knowing that our prayers will be answered according to His will, for the good of those that love Him.
I'll be developing this as time permits.