What Bible verses imply that a Christian should not use profanity?
Matthew 12:36
I tell you, on the day of judgement people will give account for every careless word they speak,
2 Timothy 2:16
But avoid irreverent babble, for it will lead people into more and more ungodliness,
Matthew 15:11
It is not what goes into the mouth that defiles a person, but what comes out of the mouth; this defiles a person.
Ephesians 4:29
Let no corrupting talk come out of your mouths, but only such as is good for building up, as fits the occasion, that it may give grace to those who hear.
Romans 12:2
Do not be conformed to this world, but be transformed by the renewal of your mind, that by testing you may discern what is the will of God, what is good and acceptable and perfect.
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.