When the Bible cautioned Christians to avoid outbursts of anger, it also mentioned avoiding the use of obscene language that often accompanies it:
“Put them all away from you, wrath, anger, badness, abusive speech, and obscene talk out of your mouth.” (Colossians 3:8)
In a different manner, sometimes obscene language is often used in a casual way including being used to humor others. The Bible also addresses this subject known as "obscene (or coarse) jesting". The apostle Paul wrote to the Christians in Ephesus:
“Let fornication and uncleanness of every sort or greediness not even be mentioned among you, just as it befits holy people; neither shameful conduct nor foolish talking nor obscene jesting, things which are not becoming.” (Ephesians 5:3, 4) Clearly, obscene language, regardless of its intent, is offensive to God.
It is true that even though we all sin with our tongue, especially in the environment of sarcasm and backbiting that we live in (James 3:2), true Christians understand from scriptural counsel not to adopt a casual attitude toward abusive speech since God clearly disapproves of all speech that injures.
The Bible counsels us: “Let a rotten saying not proceed out of your mouth.” (Ephesians 4:29)
Avoiding obscene speech begins with learning to control the emotions and actions that lead up to it. The Bible identifies these:
“Let all malicious bitterness and anger and wrath and screaming and abusive speech be taken away from you.” (Ephesians 4:31)
The Bible commands for us to not allow anger to cause us to use obscene language: “Let nothing go forth unrestrained from your mouth.” (1 Samuel 2:3)
By filling your mind with proper thoughts, you will be building up right desires of the heart. This will affect your speech. Jesus stated: “For out of the abundance of the heart the mouth speaks.” (Matthew 12:34)
By our own vigilance to control our tongue, coupled with God’s backing, we will be able to avoid the snare of profanity. The psalmist prayed: “Do set a guard, O Jehovah, for my mouth; do set a watch over the door of my lips.” (Psalm 141:3)
For more, see:
Abusive Speech; Obscene Talk (Search Results From the Watchtower Online Library)