The real issue is whether or not tongues SHOULD BE USED in this manner.
1. There is NOT A SINGLE DIRECTIVE in Scripture to pray in any other language than the normal language which you use for everyday speech.
1 Cor 14:
5) I would that ye all spake with tongues, but rather that ye prophesied: for greater is he that prophesieth than he that speaketh with tongues, except he interpret, that the church may receive edifying.
15) What is it then? I will pray with the spirit, and I will pray with the understanding also: I will sing with the spirit, and I will sing with the understanding also.
28) But if there be no interpreter, let him keep silence in the church; and let him speak to himself, and to God.
2. There is absolutely no merit awarded to anyone for praying in foreign languages or mouthing gibberish.
While there is certainly no merit to mouthing gibberish, there is a lot of value in speaking in tongues.
Acts 2:
11) Cretes and Arabians, we do hear them speak in our tongues the wonderful works of God.
Acts 10:
46) For they heard them speak with tongues, and magnify God. Then answered Peter,
1 Cor 14:
2) For he that speaketh in an unknown tongue speaketh not unto men, but unto God: for no man understandeth him; howbeit in the spirit he speaketh mysteries.
4) He that speaketh in an unknown tongue edifieth himself; but he that prophesieth edifieth the church.
17) For thou verily givest thanks well, but the other is not edified.
3. God is not glorified if a strange language is used to address Him, when Christ taught us to pray with simplicity and sincerity.
The Bible states that when a person speaks in tongues he is speaking the wonderful works of God, and magnifying God. To me, that qualifies as glorifying God.
4. The meaning of 1 Corinthians 14:14,15 has been thoroughly perverted to accommodate modern "prayer language".
So what is Paul really teaching us here?
For if I pray in an unknown tongue, my spirit prayeth, but my understanding is unfruitful. What is it then? I will pray with the spirit, and I will pray with the understanding also: I will sing with the spirit, and I will sing with the understanding also.
For if I pray in an unknown tongue: The Greek text says "if I pray in a language" [supernaturally]
Right. Speaking in tongues is speaking a language, supernaturally.
my spirit prayeth: only my spirit is involved [and this is with respect to a genuine human language spoken supernaturally]
Tongues can be languages of men or angels, and they may be current languages or languages no longer used. And yes, speaking in tongues is supernatural.
but my understanding is unfruitful: my mind and my thoughts are not involved
Yes, when a person speaks in tongues, his mind is not involved. He is not responsible for the words he says (although he is responsible to speak..).
What is it then?: one could paraphrase this in modern parlance as "And that's a shame"
That is an utterly ridiculous assertion, Nehemiah. NO translation even comes close to suggesting such a thing. If you're going to assert that "and that's a shame" is a viable translation of the Greek, show your work.
I will pray with the spirit: I will engage in genuine prayer, where my spirit communes with God
Paul is talking about speaking in tongues. "Praying in the spirit" is speaking in tongues.
and I will pray with the understanding also: I will engage my mind and my thoughts in my praying.
Praying with the understanding means praying in your known language.
So how can anyone claim that these verses are encouraging prayer language, when they are actually telling people to pray intelligently and intelligibly?
Your understanding of what those verses are saying is incorrect.