Has God’s definition of “bad words” evolved?

When Ashley and I met for coffee, she told me her story, peppered with potty language and a few "swear" words.  Should I have confronted her with Colossians 3:8: But now you must also rid yourselves of all such things as these: anger, rage, malice, slander, and filthy language from your lips? What would you have done?

        Over the last couple of decades I've observed the slow erosion of wholesome language, especially among younger Christians.  Not surprising in light of cultural disintegration, the crude soup in which we now swim. Ashley's way of expressing herself has been thoroughly influenced by that soup. But how should Christians respond? And should Believers adjust their vocabulary to accommodate the culture?  Has God's definition of "bad words" changed?
        Here's my rule of thumb: If I'm talking with a Christ-follower, I expect a gracious mouth. More about what that means in a minute. But if I'm interacting with a non-believer, I extend grace. They can't be expected to use wholesome words which means that their vocabulary will probably offend my sensitive ears.  I love the way Mike Shepherd, a Denver pastor to Millennials, says it in Keepin' It Real.  

    We use the term grace a lot in church lingo. That word taught us that everyone
    matters to God and should matter to us no matter what his or her struggle is in life.
    One thing Postmoderns do is freely admit their struggles. It can be pretty raw and
    shocking at times as they share their struggles from homosexuality to maxing out
    credit cards. Sometimes four letter words are used. But that's okay. Remember, you
    are there to mentor them. Our goal is to take them from where they are in life when
    they come to us to where God wants them to be. It takes patience, genuine care, and
    real acceptance to walk with them on that journey. It can take years. But that real
    acceptance will lead to trusting relationships that can then lead them to trust Christ
    and become followers. We must extend love and grace to all regardless of where
    they may be in life and provide a safe place during life's challenges.

Would I rather never have to listen to degrading, irreverent words? You bet. But am I willing to sacrifice my right to a "clean" world word-wise so that the Holy Spirit might use me to woo seekers to Christ? Certainly. Yes, it hurts to listen to irreverent words, but eternal destinies are at stake.  
         But what about believers who continue potty-mouth and profanity after they fall in love with Jesus? Do slang words that paint unclean pictures in some people's minds offend our Lord? Are they unfit for people who call themselves Christians? I submit that they are, and I base my argument on passages like Ephesians 5:3,4. Paul speaks clearly:  But among you there must not be even a hint of sexual immorality, or of any kind of impurity, or of greed, because these are improper for God's holy people. Nor should there be obscenity, foolish talk or coarse joking, which are out of place, but rather thanksgiving.
        I've heard Christians attempt to rationalize their off-color potty-language with all sorts of excuses: Words change as culture changes. These kinds of words don't mean what they used to mean. I'm making my non-Christians friends more comfortable when they swear. One Christian told me that her off-color language was OK because of her interpretation of the Greek.  I wonder if she uses those words when she prays? I challenge us all to look at Paul's words carefully. He says not even be a hint of any kind of impurity, obscenity, foolish talk, or coarse joking.  I'm suggesting that any word that causes any listener's mind to be drawn to the base, vulgar, sordid, or dishonorable does not fit who we are in Christ. We are called to speak whatever is true, noble, right, pure, lovely, admirable, excellent, or praiseworthy, as Paul commands in Philippians 4:8. Do our words drag down or lift up? Our words make a difference–a big difference.
       So if you love Jesus, wash your words; make them match who you are in Christ. If you are conversing with someone who doesn't know Him, give them grace—but show them how a daughter of The King sounds. They just might want to learn more about the beauty of cleaning up and the only One who is powerful enough to help us do that.