William Mounce veered a little off topic at Koinonia and wrote about how people talk about and to each other:
Does Eph 4:29 apply to blogs? (Monday with Mounce 25)

I would add 4:30 onto this discussion. Here is something I posted a few months ago:

I was reading Ephesians 4:29-30 along with O’Brien’s commentary.

Ephesians 4:29-30 NIV (which O’Brien uses)
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. And do not grieve the Holy Spirit of God, with whom you were sealed for the day of redemption.

O’Brien says:

The coordinating conjunction ‘and’ links this exhortation to the negative imperative of v. 29, so that the two clauses can be rendered: ‘let no unwholesome word come from your mouths . . . and do not grieve the Holy Spirit of God’. This latter prohibition serves as a motivation for the preceding advice about speech … The Spirit, who is the divine agent of reconciliation and unity in the body (Eph 2:18, Eph 2:22, Eph 4:3-4), is especially grieved when unwholesome speech is uttered by member against one another.

As I am still breaking the habit of taking verses in isolation and linking these two together was extremely convicting. With tears, I stopped reading and thought about my own speech, including through the keyboard, especially “only what is helpful for building others up according to their needs, that it may benefit those who listen”. This even applies to thoughts. I acknowledged my failures in this area and pray regularly that by His grace I will repent and over time learn how to communicate more gently. (See R-E-S-P-E-C-T, which I wrote shortly after God spoke to me about this.)