Be careful little tongue what you say...

Ephesians 4:29-5:7

I've often used Ephesians 4:29 as a verse to prove that swearing is wrong. Looking at it in the context, I don't think that's what it is saying. I think Paul is talking about when someone speaks in public, they should be certain that the things they are saying are true and helpful for building up those who are listening. This is a good challenge for me as I prepare to speak this Sunday - my job isn't just to entertain or have people appreciate what I say. My job is to build them up according to their needs. This might mean pointing out errors in their thinking or living or it might mean encouraging and praising them for choosing righteousness. Part of my job is to determine what they need (not what they want necessarily) and to meet that need through the Scriptures.
Paul is continuing his list of things that we should strip off and things we should put on instead. Change out of unwholesome talk and put on what builds up others. I think this applies beyond just public speaking. I think this means that we should be careful with our sarcasm and joking and our conversations in general. Does what I say build others up? Paul gets back to this in 5:4 - strip off obscenity, foolish talk (that's a pretty broad category...) and coarse joking and put on thanksgiving. This seems like a pretty unusual replacement - it isn't obvious that thanksgiving would replace obscenity, etc. But when I think about it, most obscenity comes from feeling put out or from feeling like something unjust has happened to me. The best thing to switch from feeling "robbed" is to cultivate thankfulness for all I have been given.
There's lots more that could be said from this passage but I think I'll leave it there for now.