Luke reports that, on the day of Pentecost,
suddenly there came from heaven a sound like a mighty rushing wind, and it filled the entire house where they were sitting. And divided tongues as of fire appeared to them and rested on each one of them. And they were all filled with the Holy Spirit and began to speak in other tongues as the Spirit gave them utterance (Acts 2:2-4).
This is one of several mentions of speaking in tongues in the Bible. It’s mentioned several times in Acts, and the major discussion with it outside Acts is in 1 Corinthians 12-14.
In the nineteenth century, the term glossolalia was coined to refer to speaking in tongues (Greek, glóssa = “tongue” and lalia = “speech”). However, in the twentieth century, this term became involved in a controversy about the nature of the tongues in question.
In the Pentecostal and Charismatic movements, it is sometimes held that “glossolalia” involves not real human languages, but “private prayer languages” that God enables one to speak.
Consequently, some have begun to refer to miraculously speaking a real foreign language as xenoglossy (Greek, xenos = “stranger, foreigner” and glóssa = “tongue”).
What happened on Pentecost itself?
It’s clear that the manifestations the disciples witness are caused by the Holy Spirit, since they begin speaking in other tongues “as the Spirit gave them utterance.”
The sound of the mighty, rushing wind signals the arrival of the Holy Spirit, and the “tongues as of fire” (i.e., individual flames) that rest on each of them signify empowerment to speak in tongues. (It’s providential that both an individual flame and a language can be spoken of as a “tongue.”)
But what about the tongues that they began speaking in? What were they?
The normal meaning of “other tongues” would be foreign languages—i.e., ones other than the Aramaic the disciples would have known from their upbringing.
This is confirmed by the text, which goes on to say, “Now there were dwelling in Jerusalem Jews, devout men from every nation under heaven. And at this sound the multitude came together, and they were bewildered, because each one was hearing them speak in his own language” (2:5-6).
This means that the disciples were speaking not in private prayer languages, but in real-world languages that the international crowd of Jews already knew.
However, some have proposed that something different was happening. Focusing on the statement that “each one was hearing them speak” in these languages, some have held that this is really a “miracle of hearing” rather than a miracle of speaking.
In other words, the disciples were still speaking in their native Aramaic, but the crowd were hearing them in whatever their own native languages were.
This is a creative idea, but it is poor exegesis. The word “hearing” is consistent with both the idea that the disciples were miraculously speaking foreign languages and with the idea that the crowd was miraculously hearing foreign languages.
After all, if one of the disciples was miraculously speaking in Latin, then one of the visitors from Rome (2:10-11) would obviously hear him speaking in Latin. The word “hearing” thus doesn’t prove one interpretation over the other.
We thus need to take a step back and look at how the text conceptualizes the miracle, and here we do get an answer. Luke explicitly states that the disciples “began to speak in other tongues.”
He conceptualizes the miracle as taking place on the part of the disciples—not on the part of the crowd. The miracle is happening as soon as the disciples begin speaking; he doesn’t present it as beginning when others start hearing what is said.
The fact that this passage and others in the New Testament refer to the miracle as speaking in tongues rather than hearing in tongues strongly indicates that it is a miracle of speaking.
This is also indicated in 1 Corinthians 12. Paul distinguishes between the gift of speaking in tongues and the gift of interpreting tongues (12:10, 30), and in 1 Corinthians 14:5-19, Paul makes it absolutely clear that speaking in tongues is not understood by itself. It requires someone who can interpret the tongue, so this is not a miracle of hearing.
In fact, Paul indicates that without an interpreter, not even the person speaking in tongues mentally knows what he is saying (14:13-14, 19).
(Some have argued that the “speaking in tongues” mentioned in Acts is different from the one mentioned in 1 Corinthians, but this is exegetically unsound. If that were the case, then the companions Luke and Paul would not use the same name for two different phenomena.)
We thus have very strong evidence that on the day of Pentecost, the disciples were miraculously enabled (by those “tongues as of fire”) to speak actual, real-world languages that they didn’t know.
This does not mean that the Holy Spirit cannot give other, related charismatic gifts. In 2016, the Congregation (now Dicastery) for the Doctrine of the Faith published a document titled Iuvenescit Ecclesia in which it noted that, although there are several lists of charismatic gifts in the New Testament, “none of these lists claims to be exhaustive” (6) and that “there has never been a shortage of different charisms arising in the temporal course of ecclesial history” (9), including the charisms that inspire new movements.
I thus don’t have any problem with the idea of new charismatic gifts being given in new eras. If God wants to do miracles of hearing or give private prayer language in later Church history, that’s up to him.
It’s just not what Luke described happening on the day of Pentecost.