From This article on desiringgod.org

Using the words commonly thought to be offensive in the culture seems to me to be sort of the verbal equivalent of not wearing deodorant and having body odor, or of going around with spilled food on our shirts all the time. Someone might argue that not wearing deodorant or wearing dirty clothes are not morally wrong things in themselves, but my response is that they do give needless offense and cause others to think of us as somewhat impure or unclean. So, I think, does using words commonly thought to be “obscene” or “offensive” or “vulgar” in the culture generally. Plus it encourages others to act in the same way. So in that way it brings reproach on the church and the gospel.

Read the article on www.desiringgod.org. I know we’ve discussed this some, but Grudem has some good thoughts on it. The article is adressed to John Piper as a response to Piper’s use of offensive langauge at a Passion conference. Piper had said something along the lines of “Sometimes God kicks our ass” (see here).

-Riley