Paul thanked God that he spoke in more tongues than any of them, should look into that from my side, as assumed that meant more than just"natural" learned languages that he knew!
As you know I'm sure, the term "unknown" was added in the KJV in italics, meaning it was not in the original language. There actually were non-Christian cults in the 1st century that spoke in unknown tongues like modern Charismatics. However, the normal meaning for the Greek word
glossa was simply the human tongue or a language. This is proven by the fact that every single usage but one in Revelation means language (5:9, 7:9, 10:11, 11:9, 13:7, 14:6, 17:15), and the one exception means the human tongue (16:10), just as the four usages in James meant human tongue.
Without a special context of one of those non-Christian cults, a first century Greek reader would assume "language" when he read Paul's statement in 1 Cor. 14:18. And concerning Corinth, it was a port city with many from other countries, so they all spoke several languages. It's hard for me to think of "unknown tongues" in Corinthians for that reason. I've preached in an international church with interpretation into Chinese, Thai and Japanese. It would have been chaos if the "tongues" or languages had not been regulated, just as Corinth was.
There is evidence that the Corinthian tongues were miraculous, but there is still no evidence that they were "unknown" tongues, since they could be interpreted. Therefore for a modern tongues-speaker to be Biblical, he or she should speak a real, existing language by a miracle, and evangelize or prophesy. This does not happen in the modern movement.
Historical side note: according to a history I have of the Pentecostal movement by a Pentecostal scholar, after the Azuza St. revival they sent missionaries out assuming they would be able to speak languages without language school, but that effort failed. I myself went to Japanese language with Pentecostals.
This has always been something that I still have not come to a full understanding on...
I appreciate your humility.
Were the "public' Gift/use of Biblical tongues within the local church JUST of a revelatory nature, as the Bible canon not closed yet? IF that was ALL the time, would cease today, as we have the completed Word BUT IF the HS also was guiding/exhorting/encorage the people during their use, would not that still apply in some fashion to/for us today?
I still find no Scripture for a private prayer language. The tongues in Corinthians were clearly for the purpose of blessing others, not for blessing one's self. If you've won folks to Christ with your tongue, well....
I'm enjoying it.
Edited in: another proof that
glossa normally means language is that
dialektos, which always means language (and is the source of our English word dialect) occurs in Acts 2:6 & 8 as a synonym for
glossa.