Mike,
Contrary to popular belief not everyone that posts here is 'Baptist'.
I personally am a 'tongue-talking' member of an Assemblies of God Church. Big Deal!
I am *not* in favor of discussing the issue of 'tongues' if it is going to become divisive.
It's simply not worth it. It's not a 'salvation issue' so it's not worth separating pathways.
I will try to answer your questions. Probably not very well, though. As I am not more passionate about tongues than Jesus.
What is the purpose of tongues?
a) edification of the body
b) sign to unbelievers
c) private "prayer language"
d) a combination of any of the above
A combination of all of the above.
It edifies the body when excersized as a 'directed' Gift or Manifestation of the Spirit's Presence.
I say 'directed' because all to often various members of Pentecostal Denom let their emotion get the better of them and they speak out publicly when it should be as a prayer language.
Then the error is compounded when someone tries to put an 'interpretation' of the 'tongues' that were never intended to be 'spoken out' to the whole body.
Sad, but, all to common. I can't understand why discerning 'Baptists' have such grief with the practice!
It has been a sign to unbelievers. Unfortunately this tends to be anecdotal and if you don't know the witness you'd tend to not believe it.
I know of two cases were tongues were spoken publicly in a meeting and then not interpreted. This caused a good deal of consternation because the person speaking was known to be reasonably self-controlled and not likely to speak out of turn.
However, in each of these cases a day or two later it was learned that a visitor was in the meeting who had received a very precise Word from the Lord in their native dialect. One somewhat obscure and definitely not taught in school.
For me it tends to be 'Private Prayer Language'. There are times when I simply don't know what to pray. And, the Spirit makes intercession through me with groans and utterances.
To be sure I've known 'Baptists' who prayed just as effectively and ended up just as exhausted but having done so in English.
For me I am convinced it's for today. That Signs, Wonders, Miracles, and all Nine Gifts (or Manifestations of the Spirits Presence) continue through today.
The real question, in this forum, though, Is not about tongues but about Jesus. And, whether a person is *really* sold out for Jesus.
It could be an interesting discussion. On the other hand it could turn into a free-for-all.