2 Corinthians 11:6, KJV: But though I be rude in speech, yet not in knowledge; but we have been throughly made manifest among you in all things
A lot of people would like to believe, most likely in order to satisfy the manifestation of their own childish egocentricity, that this verse is a justification of rude speech as we would use the word 'rude' in English contemporarily. If written today, we could safely assume the verse would be likely to refer particularly with respect to speech, forms of rudeness include acting inconsiderate, insensitive, deliberately offensive, impolite, obscenity, profanity and violating taboos such as deviancy with contention at its core.
However due diligence would incline us towards an investigation of the word in which was originally used in the text as written by its authors in the language it was written in, at the time it was written.
(2 Corinthians 11:6 ) refers to one who is ignorant or unskilled at something specifically in this case, in speech. This is very evident when we look into the Greek word idiotes which was actually the word used originally in lue of 'rude'. This is the same root of the English word idiot, which again reffers to someone who is stupid or archaically, a person of low intellegence, again in this context concerning speech but not knowledge.
Paul most likely meant that his speech did not meet the standards of Greek oratory or perhaps he merely wasn't as articulate as those who he compared himself against in that verse yet his knowledge still exceeded theirs.
Lexicon :: Strong's G2399 - idiōtēs
The KJV translates Strong's G2399 in the following manner: unlearned (3x), ignorant (1x), rude (1x).
🥇Proverbs 15:4 A wholesome tongue is a tree of life: but perverseness therein is a breach in the spirit.