Tongues - Heavenly or human Language

1 Corinthians 14:5-6, ". . . 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. Now, brethren, if I come unto you speaking with tongues, what shall I profit you, except I shall speak to you either by revelation, or by knowledge, or by prophesying, or by doctrine? . . ."
The early churches did not have the complete written New Testament as of Paul's writing this letter to this Corinthian church.

 

In 1 Corinthians 14 where Paul speaks of the Gifts of the Holy Spirit, and spends much time on the Gift of Tongues, he says in verse 21:

"It is written in the law: I will speak to these people by people of other languages and by the lips of foreigners, and even then, they will not listen to Me, says the Lord"

Which is from Isaiah 28:11-12, where the passage is about human languages and not "heavenly"

In Acts 22:2, when Paul retells his conversion, he says that Jesus spoke to him in Hebrew, and not a "heavenly" language

"And when they heard that he spoke to them in the Hebrew language, they kept all the more silent. Then he said"

Ἑβραΐδι, which is actually Aramaic

Pentecostals wrongly use 1 Corinthians 13:1, to try to "prove" thay they can speak in a "heavenly language"

"If I speak human or angelic languages"

The conditional particle, ἐάν, does not mean that Paul did speak in a "heavenly language"; but means, "even suppose I were to". His arugment here about have all "Gifts", but lacking in love