Lying: What the Church Teaches and How to Stop

1. What Is a Lie, According to the Church?

The Catholic Church defines a lie, in words taken from St. Augustine, as "speaking a falsehood with the intention of deceiving" (CCC 2482). Two things make a lie: saying what you believe is false, and meaning to make someone believe it. An honest mistake is a different thing. So is a joke everyone knows is a joke, or a story told as fiction. The Catechism adds that "lying is the most direct offense against the truth. To lie is to speak or act against the truth in order to lead into error someone who has the right to know the truth" (CCC 2483).

Maybe a lie is weighing on you right now. A small one that grew, a cover story you now have to keep up, a secret your spouse or your parents still do not know. Maybe lying has simply become the easiest way through the day, and you are tired of it. That tiredness is a good sign. It means your conscience is awake, and it is calling you home to the truth.

Jesus takes lying seriously because he takes truth personally. He calls himself "the way, and the truth, and the life" (John 14:6), and he names the devil "a liar and the father of lies" (John 8:44, quoted in CCC 2482). Every time we choose the truth, we side with Christ.

2. Is Lying a Sin, and Is It Ever a Mortal Sin?

Lying is always a sin, and it is usually venial. It becomes mortal when it does serious harm. The Catechism says: "The gravity of a lie is measured against the nature of the truth it deforms, the circumstances, the intentions of the one who lies, and the harm suffered by its victims. If a lie in itself only constitutes a venial sin, it becomes mortal when it does grave injury to the virtues of justice and charity" (CCC 2484).

Some examples help:

• Telling a friend you love the sweater she knitted when you do not is a lie in a light matter.
• Lying on a tax return, falsifying a résumé, or lying to a spouse about an affair or hidden debt can do grave harm to justice and trust.
• Lying under oath is perjury, and false witness in court "gravely compromise[s] the exercise of justice" (CCC 2476).
• Lying about another person to damage their reputation is calumny. See our guide to gossip and detraction.

For any sin to be mortal it must also be done with full knowledge and deliberate consent (CCC 1857). Panic, fear and long habit can reduce responsibility (CCC 1735). They do not make lying good, and they are a reason to seek healing as well as forgiveness.

What about white lies?

White lies are real lies, and they are usually venial. The Church holds that "by its very nature, lying is to be condemned. It is a profanation of speech, whereas the purpose of speech is to communicate known truth to others" (CCC 2485). St. Augustine wrote two whole treatises, On Lying and Against Lying, arguing that even a well-meant lie is still a lie, and St. Thomas Aquinas follows him (Summa Theologiae II-II, q. 110). The good news is that kindness rarely needs a lie. "Thank you, you made this for me" is true and warm. Learning to find the true kind thing to say is part of growing in charity.

3. Why Does Truth Matter So Much?

Truth matters because every relationship, from friendship to marriage to society, rests on trust. The Catechism puts it simply: "Men could not live with one another if there were not mutual confidence that they were being truthful to one another" (CCC 2469). A lie breaks that confidence. "It contains the seed of discord and all consequent evils. Lying is destructive of society; it undermines trust among men and tears apart the fabric of social relationships" (CCC 2486).

You have probably felt this. Once you catch someone in a lie, you start to wonder what else was untrue. The Catechism says a lie "does real violence to another. It affects his ability to know, which is a condition of every judgment and decision" (CCC 2486). When we lie to someone, we make their decisions for them by feeding them false information.

Lying also harms the liar. You have to remember what you said and to whom. You live with a low hum of fear that it will come out. Over time you can lose track of what is true even inside yourself. The Catechism describes the honest person as one who shows "oneself true in deeds and truthful in words," guarding "against duplicity, dissimulation, and hypocrisy" (CCC 2468). That kind of person sleeps well.

Scripture is blunt about how God sees it: "Lying lips are an abomination to the LORD, but those who act faithfully are his delight" (Proverbs 12:22). The story of Ananias and Sapphira, who lied to the apostles about the price of their land, shows how seriously the early Church took a lie told to God and his people (Acts 5:1-11). The eighth commandment, "You shall not bear false witness against your neighbor" (Exodus 20:16), protects the truth that lets us live together.

4. Do I Have to Tell Everyone Everything?

Honesty never requires telling everyone everything. The Catechism is clear: "The right to the communication of the truth is not unconditional" (CCC 2488). It continues: "The good and safety of others, respect for privacy, and the common good are sufficient reasons for being silent about what ought not be known or for making use of a discreet language. ... No one is bound to reveal the truth to someone who does not have the right to know it" (CCC 2489).

This gives a lot of freedom. You may keep a confidence. You may decline to answer a nosy question: "I'd rather not talk about that." A doctor may keep a patient's records private, and a priest keeps the seal of confession absolutely. Silence, discretion and tactful words are legitimate.

Moral theologians have long debated the hardest cases, such as the famous example of a murderer at the door asking where his victim is hiding. Without settling every debate, the Catechism's principles point the way: you are never obliged to hand the truth to someone who has no right to it and would use it to do evil, and you may protect the innocent with silence and discreet language. In ordinary life, situations like that are rare. Most of our lies are told to avoid embarrassment, conflict or consequences.

Related sins against the truth

• Flattery: the Catechism forbids "every word or attitude ... which by flattery, adulation, or complaisance encourages and confirms another in malicious acts" (CCC 2480).
• Boasting: "Boasting or bragging is an offense against truth" (CCC 2481). Exaggerating our achievements online is a modern form of it, and it often grows from pride.
• Mocking irony: the same paragraph names "irony aimed at disparaging someone by maliciously caricaturing some aspect of his behavior."

5. Why Do We Lie?

We lie mostly out of fear: fear of punishment, of disappointing someone, of conflict, or of being seen as we are. Knowing your usual reason helps you fight it.

• Fear and shame. Adam and Eve hid in the garden and blamed each other (Genesis 3:8-13). Hiding and covering is the oldest reflex of a sinner.
• Pride. We want to look better, smarter or more successful than we are. See pride and humility.
• Avoiding conflict. Saying "I'm fine" or "Sure, no problem" when it is not true can feel kinder in the moment. It slowly empties a relationship.
• Protecting another sin. Many lies exist to hide something else: drinking, spending, pornography, an affair. The lie and the hidden sin feed each other. If that is your situation, the guides to pornography, adultery and emotional affairs, and greed may help.
• Habit. For some people lying has become automatic, even about things that do not matter. That pattern can have roots in a childhood where the truth was not safe, and it often needs patient help to unlearn.

St. Peter is a comfort here. Frightened by a servant girl's question, he lied three times that he even knew Jesus (Luke 22:54-62). After the resurrection, Jesus asked him three times, "Do you love me?" (John 21:15-17), and gave him the Church to lead. A liar became the rock. There is hope for you.

6. How Do You Stop Lying?

You stop lying by slowing down before you speak, by telling the truth in small things first, and by bringing your lies into the light of confession. These steps help.

1. Pray for a truthful heart. "Behold, thou desirest truth in the inward being; therefore teach me wisdom in my secret heart" (Psalm 51:6). Pray it every morning.
2. Pause before answering. Most lies are told in the first half-second. Give yourself a breath. "Let me think about that" is always true.
3. Keep your words simple. Jesus said, "Let what you say be simply 'Yes' or 'No'" (Matthew 5:37). Fewer words, fewer exaggerations.
4. Correct yourself on the spot. If a lie slips out, say "Actually, that's not quite right" as soon as you can. It gets easier each time, and it retrains the reflex.
5. Find the kind truth. Replace white lies with true kindness: thank people for the effort, name what you genuinely appreciate, decline politely without inventing excuses.
6. Deal with the hidden sin. If you are lying to cover another habit, the lying will stop when the hidden thing is brought into the open. Start with the priest in confession.
7. Examine your conscience nightly. Did I say anything untrue today? Did I exaggerate to impress? Did I let a false impression stand when I could have corrected it? Did I keep the confidences I was given?
8. Confess specifically. "I lied to my wife about money several times this month" brings more grace than "I told some lies." See our guide to confession.
9. Find one person to be completely honest with. A spouse, a spiritual director, a trusted friend. A single fully honest relationship can anchor all the others.

St. Thomas More, the English chancellor who would not swear to what he believed was false, went to his death in 1535 rather than lie with his mouth (read his story). Most of us will never face that test. We face smaller ones every day, and he is a good friend to ask for help with them.

7. How Do You Make Things Right After Lying?

Making things right after a lie means confessing it to God and, where it is wise and possible, correcting it with the people you deceived. The Catechism teaches that "every offense committed against justice and truth entails the duty of reparation, even if its author has been forgiven" (CCC 2487). It also notes that "when it is impossible publicly to make reparation for a wrong, it must be made secretly."

Coming clean can be frightening, especially with a big lie in a marriage or at work. A few guidelines:

• Go to confession first. Receive God's forgiveness before you face anyone else. It gives you strength.
• Ask your confessor or a wise counsellor how and when to tell the person you deceived, especially if the truth will hurt them deeply. A big disclosure in a marriage is often best made with a counsellor present.
• Correct anything false you said about someone else, with the same people who heard it.
• Pay back anything you gained by the lie: money, credit, a position.
• Be patient with the other person. Trust broken by a lie returns slowly, through many small truths.

8. Hope, Mercy and When to Get Help

God already knows every lie you have told, and he still loves you completely. Confession is the place where you can finally tell the whole truth with no fear of being rejected. "If we confess our sins, he is faithful and just, and will forgive our sins and cleanse us from all unrighteousness" (1 John 1:9, quoted in CCC 1847). The relief people feel after a long-hidden lie is confessed is one of the clearest experiences of grace there is.

Do not be discouraged if old habits come back. St. Paul tells the Colossians, "Do not lie to one another, seeing that you have put off the old nature with its practices" (Colossians 3:9). Putting off an old nature takes time. Keep going back to confession, keep correcting yourself, and you will notice the change.

For the root sins that often drive lying, see the hub guide to the seven deadly sins.