Cf. 1 Corinthians 8, with "meat offered to idols" replaced by "speaking with bad language."
I will transcribe it for your reading pleasure!
1 Corinthians 8
1 Now as touching BAD WORDS, we know that we all have knowledge. Knowledge puffeth up, but charity edifieth.
2 And if any man think that he knoweth any thing, he knoweth nothing yet as he ought to know.
3 But if any man love God, the same is known of him.
4 As concerning therefore BAD WORDS, we know that A BAD WORD is nothing in the world, and that STICKS AND STONES MAY BREAK MY BONES ETC.
5 For though there be that are called BAD WORDS, whether in heaven or in earth, (as there be WORDS many, and BAD WORDS many,)
6 But to us there is but one WORD, JESUS CHRIST, BY Whom are all things, and we in him; and one EPITHET Jesus Christ, by Whom are all things, and we by Him.
7 Howbeit there is not in every man that knowledge: for some with conscience of the BAD WORD unto this hour HEAR IT AND SPEAK it as a thing offered unto DISSOLUTION; and their conscience being weak is defiled.
8 But BANDYING PHRASES commendeth us not to God: for neither, if we CURSE, are we the better; neither, if we HOLD OUR TONGUES, are we the worse.
9 But take heed lest by any means this liberty of yours become a stumblingblock to them that are weak. (italics mine)
10 For if any man see thee which hast knowledge IMITATE THE SAILOR, shall not the conscience of him which is weak be emboldened to VITUPERATE LIKEWISE;
11 And through thy knowledge shall the weak brother perish, for whom Christ died?
12 But when ye sin so against the brethren, and wound their weak conscience, ye sin against Christ.
13 Wherefore, if BAD WORDS make my brother to offend, I will CURSE NOT while the world standeth, lest I make my brother to offend.
N.B. "Sticks and stones" is, to be self-referentially perverse, bulls***. Or, as C. S. Lewis put it, damned nonsense. The notion that words can't be bad is tantamount to denying the meaning of words, which as a more perspicuous answer has pointed out, is untenable.
Along these lines it is edifying to consider instead the vast power that language has for spreading the kingdom of God, and not only with regards to apostolic spreading of the Gospel. An Alaskan native who sang in the choir asked a priest if his book had been published yet. Upon an affirmative response, the lady told him that perhaps some people would read his book. But her voice projected the words of the gospel, which reverberate unto the ends of the universe.