What does the Bible say about swearing and cursing?
Ephesians 4:29
29 Do not let any unwholesome talk come out of your mouths, but only what is helpful for building others up according to their needs, that it may benefit those who listen.
New International Version (NIV)
The answer
Scripture condemns profaning God’s name, corrupt or filthy speech, and cursing people. It also requires simple truthfulness rather than casual or deceptive oath-swearing. Words are meant to honor God and build up people made in His image.
Profanity and filthy speech
Exodus 20:7 commands, “You shall not misuse the name of Yahweh your God, for Yahweh will not hold him guiltless who misuses his name.” Using God’s name as an empty exclamation or curse profanes what is holy.
Ephesians 4:29 gives the governing rule: “Let no corrupt speech proceed out of your mouth, but only what is good for building others up as the need may be, that it may give grace to those who hear.” Colossians 3:8-9 likewise tells believers to put off anger, wrath, malice, blasphemy and filthy communication. The issue is therefore broader than a modern list of forbidden words: speech that dishonors God, degrades others, or expresses malice is sin.
Cursing people
Cursing means invoking evil against someone or speaking maliciously against them. James 3:9-10 condemns using the same tongue to bless God and curse people made in His image: “Out of the same mouth comes blessing and cursing. My brothers, these things ought not to be so.”
Romans 12:14 commands, “Bless those who persecute you; bless, and don’t curse.” Jesus requires the same response even toward enemies: “love your enemies, bless those who curse you” and pray for persecutors (Matthew 5:44). Retaliatory cursing is therefore replaced by blessing and prayer.
Swearing oaths
Jesus says, “don’t swear at all” (Matthew 5:34), concluding in Matthew 5:37: “But let your ‘Yes’ be ‘Yes’ and your ‘No’ be ‘No.’ Whatever is more than these is of the evil one.” James 5:12 repeats the command. This rules out casual oath-swearing and using oaths to make unreliable or dishonest speech sound credible.
On whether every solemn oath is forbidden, Anabaptist traditions have generally answered yes, including oaths in court. Catholic, Orthodox, and many Protestant traditions have generally distinguished such oaths from the casual or evasive swearing Jesus condemned. They note that Hebrews 6:16-17 says God confirmed His promise with an oath, while 2 Corinthians 1:23 records Paul calling God as his witness.
The heart behind the words
Jesus explains in Matthew 12:34, “For out of the abundance of the heart, the mouth speaks.” He also warns that every idle word will be brought to account in the day of judgment (Matthew 12:36). Changing speech therefore requires repentance and a changed heart, not merely substituting one set of words for another.
Such sin is not beyond Christ’s grace. First Peter 2:24 says that He bore our sins in His body on the tree so that we might die to sins and live to righteousness. First John 1:9 promises forgiveness and cleansing to those who confess their sins. The new direction is speech seasoned with grace (Colossians 4:6), truthful before God and used for the good of those who hear.
Answered from Scripture · reviewed November 11, 2026
Scripture addresses both senses of the word: swearing by taking oaths to guarantee one's speech, and cursing by uttering corrupt words or invoking harm on others. In both cases, God calls His people to radical integrity and gracious speech, revealing that the mouth reflects the true condition of the heart.
Truth and Oaths
Let Your Yes Be Yes Without Evasive Oaths
All you need to say is simply ‘Yes’ or ‘No’; anything beyond this comes from the evil one.
Matthew 5:37 (NIV)
Jesus sets the standard of total honesty, showing that elaborate oaths arise from deceit rather than integrity.
In Matthew 5:37, Jesus establishes plain truthfulness as the absolute standard for His disciples: "Let what you say be simply 'Yes' or 'No'; anything more than this comes from evil." In the ancient world, elaborate oaths were frequently invoked to convince others of sincerity or to manufacture technical loopholes for breaking one's word. The third commandment laid the foundation for reverent speech in Exodus 20:7 by forbidding anyone from taking the Lord's name in vain, a mandate reinforced in Leviticus 19:12, where God strictly prohibits swearing falsely by His holy name and profaning His sanctuary. Moses taught in Deuteronomy 6:13 that solemn civil oaths belonged to God alone, while Deuteronomy 23:21-23 and Numbers 30:2 warned that any vow voluntarily uttered before the Lord must be faithfully and punctually performed. Ecclesiastes 5:4-5 similarly counsels that it is far better never to vow at all than to vow and fail to pay.
In Matthew 5:33-37 and Matthew 23:16-22, Christ strips away every Pharisaic pretense that treated oaths sworn by heaven, the earth, the temple, or the altar as negotiable tiers of honesty. God hears every utterance directly, making all evasive oaths an indictment of inner deceit. James 5:12 echoes his Lord almost verbatim, urging believers above all things not to swear by heaven, earth, or any other oath, lest they fall under condemnation through double-minded speech. When Scripture records God confirming His covenant to Abraham with an oath in Hebrews 6:13-17, or Paul solemnly invoking God as witness in 2 Corinthians 1:23, it demonstrates that solemn appeals to truth in formal contexts are not forbidden; rather, frivolous, misleading, and routine swearing is exposed as an evasion of basic integrity.
| Passage | What it says |
|---|---|
| Exodus 20:7 | The third commandment forbids misusing God's holy name, including swearing falsely by Him. |
| Leviticus 19:12 | Israel is forbidden to swear falsely by God's name or profane it through deceitful promises. |
| Matthew 5:33-37 | Jesus warns against using oaths as bargaining chips and commands straightforward, truthful speech. |
| Matthew 23:16-22 | Jesus rebukes the scribes and Pharisees for creating legalistic loopholes around different oath formulas. |
| James 5:12 | James commands believers above all not to swear oaths, keeping their simple yes or no true. |
| Hebrews 6:13-17 | God's own sworn promise confirms His unchangeable purpose to heirs of the covenant. |
| 2 Corinthians 1:23 | Paul calls God as a witness to the sincerity and purpose of his apostolic conduct. |
| Deuteronomy 6:13 | Moses instructs Israel to fear the Lord and swear by His name alone in solemn, holy commitments. |
| Deuteronomy 23:21-23 | Vows made to God must not be delayed or broken, though refraining from vowing is not sin. |
| Numbers 30:2 | A person who swears an oath must not break their word but perform all they promised. |
| Ecclesiastes 5:4-5 | It is better not to vow than to make a vow to God and fail to pay it. |
Blessing Over Cursing
Call Down Blessing Instead of Bitter Harm
Bless those who persecute you; bless and do not curse.
Romans 12:14 (NIV)
Paul commands believers to repay persecution with blessing, entirely forbidding vindictive curses.
In Romans 12:14, the apostle Paul issues an unmistakable ethical command: "Bless those who persecute you; bless and do not curse them." This counter-cultural posture directly reflects the teaching of the Lord Jesus Christ, who commanded His disciples in Matthew 5:44 and Luke 6:28 to love their enemies, pray for abusers, and actively bless those who invoke curses upon them. In 1 Peter 3:9, Peter reinforces this royal law of love, forbidding believers from repaying evil with evil or reviling with reviling, but instead calling them to bestow a blessing because they were called to inherit a blessing.
The gravity of uttering malicious curses is woven throughout the entire canon of Scripture. Under Mosaic law, invoking a curse upon father or mother was treated with severe severity in Exodus 21:17, Leviticus 20:9, and Proverbs 20:20, showing that dishonoring parental authority with venomous speech was a direct assault on the covenant community. Exodus 22:28 prohibited reviling God or cursing a leader of the people, while Leviticus 19:14 commanded compassion for the vulnerable by forbidding the cursing of the deaf, who could not defend themselves. The ultimate transgression was blasphemy against the Lord Himself, judged without compromise in Leviticus 24:15-16. Furthermore, Proverbs 26:2 comforts the faithful by noting that an undeserved curse has no supernatural power and flutters harmlessly away like a sparrow. Proverbs 30:10-11 and Ecclesiastes 10:20 caution against bitter slander even in secret chambers, because Romans 3:13-14 diagnoses unregenerate human nature precisely by mouths overflowing with cursing and bitterness.
| Passage | What it says |
|---|---|
| Exodus 21:17 | Cursing one's parents carried capital punishment under Mosaic law, showing the gravity of destructive words. |
| Proverbs 20:20 | Whoever curses their father or mother will see their lamp snuffed out in total darkness. |
| Matthew 5:44 | Jesus commands love toward enemies, prayer for abusers, and blessing for those who curse His followers. |
| Luke 6:28 | Jesus instructs His disciples specifically to bless those who curse them and pray for persecutors. |
| Romans 12:14 | Believers are instructed to bless those who persecute them and explicitly not to curse. |
| 1 Peter 3:9 | Peter forbids returning insult for insult, calling Christians instead to return a blessing as heirs of mercy. |
| Exodus 22:28 | God commands His people not to revile God nor curse a ruler of the people. |
| Leviticus 19:14 | The law forbids cursing the deaf or putting a stumbling block before the blind. |
| Leviticus 20:9 | Anyone who curses father or mother incurs severe covenant judgment. |
| Leviticus 24:15-16 | Whoever curses God bears their sin, and anyone who blasphemes the Name must be judged. |
| Proverbs 26:2 | An undeserved curse does not come to rest, fluttering away like a sparrow or swallow. |
| Proverbs 30:10-11 | Slandering a servant or cursing parents brings guilt and marks a corrupt generation. |
| Ecclesiastes 10:20 | A warning against cursing the king or the rich even in private thought or bedroom. |
| Romans 3:13-14 | Paul quotes Scripture to show unredeemed humanity has mouths full of cursing and bitterness. |
The Heart and the Tongue
Words Reveal the Real State of the Heart
With the tongue we praise our Lord and Father, and with it we curse human beings, who have been made in God’s likeness. Out of the same mouth come praise and cursing. My brothers and sisters, this should not be.
James 3:9-10 (NIV)
James exposes the tragic hypocrisy of praising God while using that same mouth to curse fellow image-bearers.
In James 3:9-10, the apostle unmasks the terrifying duplicity of the unbridled tongue: "With it we bless our Lord and Father, and with it we curse people who are made in the likeness of God. From the same mouth come blessing and cursing. My brothers, these things ought not to be so." Across James 3:1-12, the tongue is depicted as a tiny spark that sets an entire forest ablaze, a restless evil full of deadly poison that no human being can tame apart from divine grace. Words do not originate in a vacuum; they provide an infallible diagnostic window into the soul. As Jesus taught in Matthew 12:34-37 and Matthew 15:18-19, the mouth speaks out of the overflow of the heart, and it is what comes out of the mouth that defiles a person, because every careless word will be accounted for on the day of judgment.
The wisdom literature and the Psalms repeatedly warn of the destruction caused by corrupt speech. Proverbs 18:21 solemnly declares that death and life are in the power of the tongue, and those who love it will eat its fruit. In contrast to the godly who cry out with David in Psalms 141:3, asking the Lord to set a guard over their mouth and keep watch over the door of their lips, the ungodly are characterized by toxic speech. Psalms 10:7 describes the wicked as having mouths full of curses, deceit, and oppression, while Psalms 59:12 and Psalms 109:17-18 show that the person who loves cursing will inevitably be consumed by it, finding it soak into their bones like oil. Proverbs 12:18 and Proverbs 13:3 remind us that reckless words pierce like swords, while prudent restraint preserves life.
| Passage | What it says |
|---|---|
| Matthew 12:34-37 | Jesus teaches that the mouth speaks from the heart's abundance, and every idle word faces judgment. |
| Matthew 15:18-19 | Defilement comes from what emerges out of the mouth, because words flow directly from the inner heart. |
| James 3:1-12 | James describes the tongue as an unruly fire and shows the contradiction of blessing and cursing together. |
| Proverbs 18:21 | Life and death reside in the power of the tongue, and speakers eat its fruit. |
| Psalms 141:3 | David prays for God to set a guard over his mouth and keep the door of his lips. |
| Psalms 10:7 | The wicked man's mouth is described as full of cursing, deceit, and oppression. |
| Psalms 59:12 | David prays regarding wicked enemies trapped by the cursing and lies they utter. |
| Psalms 109:17-18 | The adversary who loved cursing finds it soaking into his body like water and oil. |
| Proverbs 12:18 | Rash words pierce like a sword, but the tongue of the wise brings healing. |
| Proverbs 13:3 | Guarding one's mouth preserves life, while opening lips wide leads to ruin. |
Edifying Speech
Speak Words That Impart Grace to Hearers
Do not let any unwholesome talk come out of your mouths, but only what is helpful for building others up according to their needs, that it may benefit those who listen.
Ephesians 4:29 (NIV)
Paul sets the standard for speech: nothing corrupt is to come out, only what builds up and imparts grace.
In Ephesians 4:29, the apostle Paul sets down the architectural blueprint for Christian conversation: "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." Rather than using words to vent anger, tear down rivals, or entertain through shock value, the believer's vocabulary is to be intentionally constructive. Ephesians 5:4 specifically excludes filthiness, foolish talk, and crude joking as entirely out of character for the saints, replacing them with expressions of thanksgiving. In Colossians 3:8-9, Paul commands believers to strip off the old self, explicitly discarding foul language, abusive speech, slander, and lying. In its place, Colossians 4:6 urges: "Let your speech always be gracious, seasoned with salt, so that you may know how you ought to answer each person."
This call to wholesome, life-giving speech fulfills the ancient wisdom of Proverbs 15:1-4, which observes that a soft answer turns away wrath, while a gentle tongue serves as a tree of life. Proverbs 15:7 and Ecclesiastes 10:12 explain that while the lips of the wise disperse knowledge and utter gracious words, the mouths of fools swallow them up in strife. Proverbs 10:19 notes that when words are many, transgression is unavoidable, making disciplined restraint the mark of true wisdom. Paul exhorts the church in 1 Thessalonians 5:11 to continually encourage one another and build each other up, an attitude echoed in Titus 3:2, where Christians are commanded to speak evil of no one. Finally, 1 Peter 2:1 and 1 Peter 3:10 remind us that anyone who desires to love life and see good days must decisively turn away from slander and keep their tongue from deceit.
| Passage | What it says |
|---|---|
| Ephesians 4:29 | No unwholesome talk should emerge; only what is beneficial for building up according to the need. |
| Ephesians 5:4 | Obscenity, foolish talk, and coarse joking are out of place, replaced instead with thanksgiving. |
| Colossians 3:8-9 | Believers must rid themselves of anger, wrath, malice, slander, and filthy communication. |
| Colossians 4:6 | Christian conversation must always remain gracious and seasoned with salt to answer everyone properly. |
| 1 Thessalonians 5:11 | Paul exhorts the church to continually encourage one another and build each other up. |
| Proverbs 15:1-4 | A gentle answer turns away wrath, while a soothing tongue serves as a tree of life. |
| Proverbs 15:7 | The lips of the wise spread knowledge, unlike the misguided hearts of fools. |
| Ecclesiastes 10:12 | The words from the mouth of a wise person are gracious, while a fool's lips consume him. |
| Proverbs 10:19 | Sin is not absent when many words are spoken, but holding one's tongue is wise. |
| Titus 3:2 | Believers are charged to speak evil of no one, avoiding quarreling and showing courtesy. |
| 1 Peter 2:1 | Believers must put away all malice, deceit, hypocrisy, envy, and all slander. |
| 1 Peter 3:10 | Those who desire life and good days must keep their tongue from evil and deceit. |
Where in the Bible
| Book | Passages |
|---|---|
| Exodus | 3 · Exodus 20:7, Exodus 21:17, Exodus 22:28 |
| Leviticus | 4 · Leviticus 19:12, Leviticus 19:14, Leviticus 20:9, Leviticus 24:15-16 |
| Numbers | 1 · Numbers 30:2 |
| Deuteronomy | 2 · Deuteronomy 6:13, Deuteronomy 23:21-23 |
| Psalms | 4 · Psalms 141:3, Psalms 10:7, Psalms 59:12, Psalms 109:17-18 |
| Proverbs | 9 · Proverbs 20:20, Proverbs 26:2, Proverbs 30:10-11, Proverbs 18:21, Proverbs 12:18, Proverbs 13:3, Proverbs 15:1-4, Proverbs 15:7, Proverbs 10:19 |
| Ecclesiastes | 3 · Ecclesiastes 5:4-5, Ecclesiastes 10:20, Ecclesiastes 10:12 |
| Matthew | 5 · Matthew 5:33-37, Matthew 23:16-22, Matthew 5:44, Matthew 12:34-37, Matthew 15:18-19 |
| Luke | 1 · Luke 6:28 |
| Romans | 2 · Romans 12:14, Romans 3:13-14 |
| 2 Corinthians | 1 · 2 Corinthians 1:23 |
| Ephesians | 2 · Ephesians 4:29, Ephesians 5:4 |
| Colossians | 2 · Colossians 3:8-9, Colossians 4:6 |
| 1 Thessalonians | 1 · 1 Thessalonians 5:11 |
| Titus | 1 · Titus 3:2 |
| Hebrews | 1 · Hebrews 6:13-17 |
| James | 2 · James 5:12, James 3:1-12 |
| 1 Peter | 3 · 1 Peter 3:9, 1 Peter 2:1, 1 Peter 3:10 |
The story in order
- God gives the law (c. 1450 BC) · Exodus 20:7 · Forbids misusing God's name, including false oaths.
- Israel's vows and curses (c. 1450 BC) · Leviticus 19:12 · Prohibits false oaths and profaning God's name.
- Wisdom on vows (c. 950 BC) · Ecclesiastes 5:4-5 · Better not to vow than to break a vow.
- Jesus teaches on oaths (c. AD 30) · Matthew 5:33-37 · Commands truthful speech, not using oaths as bargaining chips.
- Jesus rebukes oath loopholes (c. AD 30) · Matthew 23:16-22 · Condemns legalistic distinctions in oath-taking.
- Jesus commands blessing enemies (c. AD 30) · Matthew 5:44 · Calls for love and prayer for those who curse us.
- Jesus on words from the heart (c. AD 30) · Matthew 12:34-37 · Mouth speaks from heart's abundance; words face judgment.
- Paul on God as witness (c. AD 55) · 2 Corinthians 1:23 · Calls God to witness sincerity and purpose.
- James on simple speech (c. AD 60) · James 5:12 · Believers' yes should be yes, their no should be no.
- James on the tongue (c. AD 60) · James 3:1-12 · The tongue is a powerful, unruly force.
- Peter on returning blessings (c. AD 60) · 1 Peter 3:9 · Do not return insults; return a blessing.
- Paul on edifying speech (c. AD 60) · Ephesians 4:29 · Speak only what builds others up.
Key words
- Swear (שָׁבַע (shava'))
- To take an oath, making a solemn promise or statement, often invoking God. · Deuteronomy 6:13
- Curse (אָרַר ('arar))
- To invoke harm or evil upon someone; to revile or speak profanely. · Exodus 21:17
- Heart (לֵבָב (levav) / καρδία (kardia))
- The inner person, the seat of thoughts, emotions, will, and moral character. · Matthew 12:34
- Tongue (לָשׁוֹן (lashon) / γλῶσσα (glōssa))
- The organ of speech; metaphorically, speech itself and its power. · Proverbs 18:21
- Edify (οἰκοδομή (oikodomē))
- To build up, instruct, or improve morally or spiritually. · Ephesians 4:29
- Gracious (χάριτι (chariti))
- Characterized by kindness, courtesy, and pleasantness in speech. · Colossians 4:6
God does not merely restrain our vocabulary; He transforms our speech to reflect His redemptive grace. When our speech is seasoned with salt, honest in truth, and eager to build others up, our words bring life and honor the Lord.
47 passages, each cited once.
Scripture cited
- Ephesians 4:29
- Colossians 4:6
- Colossians 3:8-9
- Matthew 12:34-37
- Exodus 20:7
- Matthew 5:33-44
- James 3:9-12
- James 5:12
- Romans 12:14
- 1 John 1:9
- 2 Corinthians 1:23
- Hebrews 6:16-17