What is speaking in tongues?
First let's look at Mark 16:17-20. In this passage, Jesus tells the disciples that they would do many signs. Verse 20 says that these signs were for the purpose of confirming the word which they preached to those who heard them. One of the signs that Jesus promised they would be able to do was to speak in new tongues. What do we find in the scriptures regarding this aspect of early Christianity?
First, the Bible teaches that speaking in tongues is merely speaking in another human language. Acts 2:1-12 is the perfect example. There, the apostles miraculously spoke in languages that other people could understand. That was the point of speaking in tongues. The gospel was young and there were many who needed to hear it. To get the gospel to the most people in a short period of time, the disciples were given the miraculous ability to speak in other human languages. These were languages previously unknown to the speaker. They were given so that there would be no cross-cultural language barrier in preaching and teaching the gospel. Those who have been to foreign countries where they speak a different language know how difficult it is to communicate. It is even more difficult when trying to communicate religious concepts. So the Lord promised the disciples that He would help in this area. Notice what 1 Corinthians 14:21 says, "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." This verse definitively states that it is with tongues of men that they spoke. We should allow it to settle the question.
Second, we find that speaking in tongues was generally abused by the church. We have a lot of detailed information on speaking in tongues in 1 Corinthians 12, 13, and 14. One of the truths contained within this passage is that tongues were going to be done away (1 Corinthians 13:8). Speaking in tongues was never intended to be a permanent part of the religion of Christ. The point Paul makes was that in exercising the gift of tongues, the abusers of this gift were not using the gift in the spirit with which the gift was intended. They were not practicing it in love. They were practicing it when an interpreter was not present so the message of the gift was not being understood. The most pertinent point regarding tongues is made in 1 Corinthians 14:22 which says, "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." Tongues were a sign for the unbeliever. They were supposed to be a help to the stranger who didn't know the gospel so that the gospel could be preached to them. Tongues were never intended to be for the believers. That's what prophecy is for (1 Corinthians 14:1).
Do we have the gift of tongues today? No. We noticed that they were going to be done away in 1 Corinthians 13:8. So what about all of those people who claim to speak in tongues today? Here is the problem with modern day tongue speakers. 1) They don't speak in human languages; they speak in alleged "angelic" tongues, so there is no way to confirm whether they are truly speaking another language or not. 2) The tongues that they speak in, they speak for their own edification, not for unbelievers. 3) They don't speak in tongues to prove what they say is true. Here are at least three things in which the Bible contradicts modern day tongue speakers.
Now, what about those "angelic" tongues? Is there any authority for speaking in "angelic" tongues based upon 1 Corinthians 13:1? The "tongues of angels" in 1 Corinthians 13:1 is first and foremost hypothetical. Paulís point is this: even if I could speak with the tongues of angels, it would do me no good if I didn't have love. We should not assume from this verse that there was some sort of angelic tongue that the early church spoke. In fact, given what we have already studied on the subject, it would be inconsistent to claim such. Another possibility is that Paul is using the Greek word "angelos" in the sense of "messenger." In other words he is discussing the tongues of "messengers." This might be someone who could speak in multiple languages. The official diplomatic messengers of the day spoke in numerous languages in order to communicate from one part of the Roman Empire to the other. We also note the languages spoken on the day of Pentecost. There would, no doubt be more, in the extent of the Roman Empire. An official messenger would need to be fluent in several to communicate official messages. This is at least one possibility other than some kind of heavenly angelic language.