I'm amazed at how many grown men have no desire to grow out of using profane language, in general, even if they do not profess to be a Christian. Growing out of that kind of thing is just a sign of maturity. It's even much worse for someone to profess to be a follower of Christ but continue to deny there's anything wrong with profanity. We are to put our old habits away.
"No rotten talk should come out of your mouth, but only what is good for the building up of someone in need, in order to give grace to those who hear." - Ephesians 4:29
