I hesitate to even answer, but I do so for the sake of those who want to learn:
1. The purpose is not for the individual to understand, but for the individual and those around to be edified.
2. If speaking in tongues is a gift of the Holy Spirit, how is that the Holy Spirit would cause anyone to say anything offensive to God???
INDEED.
I gave a very logical reply that was quite similar though very long comparatively.
There didn’t seem to be any significant interest in the Biblical truth of my assertions.
The interest seemed to be in throwing rocks regardless of how irrationally.
Logic and Scripture were evidently irrelevant.
1 Corinthians 14 Intelligibility in Worship 1 Follow the way of love and eagerly desire gifts of the Spirit, especially prophecy. 2 For anyone who speaks in a tongue[g] does not speak to people but to God. Indeed, no one understands them; they utter mysteries by the Spirit. 3 But the one who prophesies speaks to people for their strengthening, encouraging and comfort. 4 Anyone who speaks in a tongue edifies themselves, but the one who prophesies edifies the church. 5 I would like every one of you to speak in tongues,[h] but I would rather have you prophesy. The one who prophesies is greater than the one who speaks in tongues,[i] unless someone interprets, so that the church may be edified.
Who is interpreting if your prayer is in tongues?
6 Now, brothers and sisters, if I come to you and speak in tongues, what good will I be to you, unless I bring you some revelation or knowledge or prophecy or word of instruction? 7 Even in the case of lifeless things that make sounds, such as the pipe or harp, how will anyone know what tune is being played unless there is a distinction in the notes? 8 Again, if the trumpet does not sound a clear call, who will get ready for battle? 9 So it is with you. Unless you speak intelligible words with your tongue, how will anyone know what you are saying? You will just be speaking into the air. 10 Undoubtedly there are all sorts of languages in the world, yet none of them is without meaning. 11 If then I do not grasp the meaning of what someone is saying, I am a foreigner to the speaker, and the speaker is a foreigner to me. 12 So it is with you. Since you are eager for gifts of the Spirit, try to excel in those that build up the church.
2) If speaking in tongues is a gift of the Holy Spirit, how is that the Holy Spirit would cause anyone to say anything offensive to God???
How do you know it's from the Holy Spirit? What if it is a demon speaking inside you? You don't know what you're saying so for all you know, you could be cursing God. Now, I don't think you want to curse God but if you speak in tongues to God and have no idea what you're saying, there's no guarantee you're speaking words inspired by the Holy Spirit.
This also gets to my previous point where there are numerous places in the Bible that have contradictory instructions yet they are both correct. As Les Feldick would say, it's not only important what the Bible says, but also, what it doesn't say.