Are you into construction or destruction? Are you helpful or harmful? Have you got a mountain of bitterness and rage that is ready to blow, if set off? Or, does Christ take the lead in how you treat others, with compassion and forgiveness?
It would seem obvious that Christians ought not be cussing people out. If you do, it is forgivable, but should not be your normal, right? But there is another kind of foulness that some Christians take part in. The foulness of words can be described in two ways: They tear down and they are unkind.
Did you know that it was common for Christians to kill other Christians over differences for centuries? The murder starts off with words, foul words. Small foul words lead to fouler words.
Foul words (hear the referee whistle and cry "foul!") are words that are not helpful, do not build up others, and do not offer benefit.
Are your negative words helpful? Do they build up? If not, do not say them. Words that call people upward are beneficial, whereas foul words are not.
Remember that out of the heart the mouth speaks (Matt: 12:34). Those foul things we say reflect our own hearts. Cleanse our hearts, O God! Purify my heart!
When we play "Christian" but we call people foul names, what does that say about us? We need a change of heart. Our words, including our self-talk, reveal our heart's state. Bad, corrupt, or stinky words reveal a hidden heart that is in bad shape and needs Jesus.
If your heart is being discipled by Jesus, going to the cross and getting saved, then you stand a chance of talking like Christ talks. If your heart has been in his hands, open to him, and in a transformational process; then good words will come out of your mouth. Gracious, loving, and up-building words will come out of the person who hase been spends lots of time with Jesus.