Is swearing / cussing / cursing a sin?

from the old testament

• The Old Testament does not address modern cuss words directly, but it does give principles about speech. It warns against taking God’s name in vain (Exodus 20:7).
• Leviticus 19:14 forbids people from cursing the deaf person. Though the deaf person won’t hear the curse, God will. Cursing in that case disrespects the person (he is being cursed without his knowing of it) and dishonors God.
• Proverbs 20:20 shows the foolishness of cursing one’s mother an father. Cursing parents dishonors the fifth of the Ten Commandments about honoring mother and father (Exodus 20:12).
• Several verses discuss the wisdom of keeping watch of our words(Proverbs 12:18; Proverbs 15:1-2; Psalm 34:13). These principles guide us to honor God and others with our speech.

from the new testament

• To change the words that come out of our mouth, we need to change the words that go into our ears, which affect our hearts (Luke 6:45).
• Anger should not cause us to sin, including swear words spoken in anger (Ephesians 4:26; James 1:19).
• Nothing corrupt should be spoken by Christians. Rather, we should only speak in ways that build others up, our speech being full of grace (Ephesians 4:29).
• We should not, as Christians, be using our mouths to praise God and also cursing others or using profane or negative speech toward them (James 3:9-10).
• Paul advised believers in Colossae, “Let your speech always be gracious, seasoned with salt, so that you may know how you ought to answer each person” (Colossians 4:6).

implications for today

God has redeemed us and saved us from our sins so we can live for what is good and true. Swear words do not reflect God’s character and heart so should not be used by those who profess to be believers. As followers of Christ, we are called to speak in ways that honor Him. When we use profanity, we are revealing areas of ourselves that are still not sanctified. Rather, when we don’t use profanity, we show self-control, respect for others, and a desire to build up instead of tear down. Even in stressful situations, swearing does not reflect self-control and trust in God. Swearing often flows from anger, frustration, or carelessness, but guarding our speech helps us grow in Christlikeness and reflect Him to the world. By replacing harsh or crude words with words that are true, edifying, and encouraging, we point people toward the character of Christ living in us.

For those who struggle with using cusswords, many methods can help. First, stop or limit media that uses vulgar language. Movies, television, books, music, articles, comics, and video games that include bad language contribute to much of the negative input we receive. Second, spend less time around people using bad language. We are called to witness to unbelievers (Matthew 28:19-20), including those who use bad language, but if cursing is a problem area, you may need to decrease how much time you spend in such conversations. Third, replace bad words with better words. Instead of the word that usually comes to mind, practice replacing it with something else. Fourth, practice the biblical teaching of being slow to become angry. Think before you speak. Do not say sinful things in anger. God has given us His Holy Spirit to transform us from the inside out, and these practical and biblical tips can help us partner with Him as He seeks to do that. We must take accountability for our words and actions and focus on having speech that builds others up and brings glory to God.