Ephesians 4:29 (NIV)
29 Do not let any unwholesome talk come out of your mouths, but only what is helpful for building others up according to their needs, that it may benefit those who listen.

Filthy and unclean words and discourse are poisonous and infectious, as putrid rotten meat: they proceed from and prove a great deal of corruption in the heart of the speaker, and tend to corrupt the minds and manners of others who hear them; and therefore Christians should beware of all such discourse. It may be taken in general for all that which provokes the lusts and passions of others. We must not only put off corrupt communications, but put on that which is good to the use of edifying. The great use of speech is to edify those with whom we converse. Christians should endeavour to promote a useful conversation: that it may minister grace unto the hearers; that it may be good for, and acceptable to, the hearers, in the way of information, counsel, pertinent reproof, or the like. [Matthew Henry]

Novelist William Giraldi, a contributing editor to The New Republic, recently wrote an essay on the modern phenomenon of online hate mail, most often found in the comments section below an article. Comments often devolve into hate-filled insults, but Giraldi draws some conclusions that Christians could agree with. First, Giraldi writes that hate mail proves that, "People are desperate to be heard, to make some sound, any sound, in the world, and hate mail allows them the illusion of doing so. Legions among us suffer from the [boredom] and [unhappiness] of modernity, from the discontents of an increasingly [isolated] society."

According to Giraldi hate mail also means that at least someone is listening to your viewpoints�even if they hate you for it. Giraldi writes, "Part of a writer's [we could insert Christian here] job should be to dishearten the happily deceived, to quash the misconceptions of the pharisaical � to unsettle and upset. If someone isn't riled by what you write, you aren't writing truthfully enough. Hate mail is what happens when you do."