'Language' in the Bible

And my message and my preaching were not in persuasive words of wisdom [using clever rhetoric], but [they were delivered] in demonstration of the [Holy] Spirit [operating through me] and of [His] power [stirring the minds of the listeners and persuading them],

We also speak of these things, not in words taught or supplied by human wisdom, but in those taught by the Spirit, combining and interpreting spiritual thoughts with spiritual words [for those being guided by the Holy Spirit].

But if I do not know the meaning of the language, I will [appear to] be a foreigner to the one who is speaking [since he knows exactly what he is saying], and the one who is speaking will [appear to] be a foreigner to me.

nevertheless, in public worship I would rather say five understandable words in order to instruct others, than ten thousand words in a tongue [which others cannot understand].