Just for the record, I think that this question can't be resolved Biblically, I think it can only be resolved by a true testing of the spirits of the operations of the gifts today, and I don't see that happening. Specific instances of tongues should be presented and considered, as many as possible, such as by recording every instance in a church, recording the interpretations if there are any, also investigating specific prophecies, in other words expose the whole range of the phenomena that are today called the gifts of the Spirit.

We know the gifts were in operation in the apostolic church, and it's possible there was a kind of language that was not a human language that was a speaking to God in private. I don't think the Bible is clear on this point one way or the other. If it is "unknown" and yet it "edifies" oneself that seems to be a possible interpretation.

The real question that concerns us today isn't so much what powers they had in that generation, but whether or not the sign gifts were only meant for them, and possibly also for the generation of the last days as well, but not for the church in the intervening centuries. There is good reason to think this is the case from the historical fact that the gifts did in fact stop, and did not reoccur except in isolated instances until the 20th century. There is also reason to think that most, possibly all, of the examples in this last century were demonically inspired. There's been plenty of evidence of that, from the unholy environments often created where the sign gifts are in operation to the testimony of people involved in the movement that a great proportion of the phenomena are demonic.

When I began to be uneasy about my own experiences in the charismatic movement and prayed for light, God brought all kinds of things to my attention and my remembrance that helped me to begin to recognize just how much of it was not of Him, violations of scripture in supposed prophetic messages for instance. Even after that I didn't have a solid conviction that all the gifts were not of Him -- that all tongues-speakers, all prophets, all healers for instance are deceived -- until recently, and now I'm just about totally convinced, and in any case very clear that my own supposed gift of tongues is not of Him and I want to be rid of it. The way I finally arrived at this conclusion was by learning more about the history of the movement and reading particular studies of it, such as David Cloud's. To my mind the burden of proof is now on the believers to show that their tongues, their prophecies by "prophets", their healings by supposed "healers," are authentic.

I don't doubt that there are many fine godly charismatics and pentecostals who sincerely believe in the gifts for today based on their understanding of the Bible. But simply quoting the Bible doesn't resolve this question, as is shown on this thread. Until the practitioners are willing to expose all the supposed gifts to careful scrutiny and able to show that the gifts are genuine, my own conclusion is that they are deceived -- the way Catholics are sincere but deceived, and so on.