Mortal vs venial sin: the difference, with examples

A mortal sin is a grave sin committed with full knowledge and deliberate consent. It cuts you off from God's grace until you're forgiven, normally in Confession. A venial sin is a lesser sin, or a grave one done without full knowledge or full consent. It wounds your friendship with God but doesn't break it, and it can be forgiven in many ways (CCC 1855, 1862). The difference comes down to three questions: how serious was it, did you know, and did you freely choose it?

What's the difference between mortal and venial sin?

The distinction goes back to Scripture. The first letter of John speaks of sin that is deadly and sin that is not (1 John 5:16-17), and the Church has taught it ever since (CCC 1854).

The Catechism puts it this way. Mortal sin destroys charity, the love of God, in your heart, because you have turned away from God toward a lesser good. Venial sin leaves charity alive, even though it offends and wounds it (CCC 1855). Think of the difference between a friendship that's been broken and one that's been strained.

Mortal vs venial sin side by side

• What it takes. Mortal: grave matter, full knowledge and deliberate consent, all three together (CCC 1857). Venial: less serious matter, or grave matter without full knowledge or full consent (CCC 1862).
• What it does. Mortal: you lose sanctifying grace, the state of grace (CCC 1861). Venial: it weakens charity and slows your growth, but you remain in God's friendship (CCC 1863).
• How it's forgiven. Mortal: normally through Confession (CCC 1856). Perfect contrition obtains forgiveness beforehand, provided you intend to confess as soon as you can (CCC 1452). Venial: through sorrow, prayer, works of charity, receiving Communion, or Confession (CCC 1394, 1434, 1458).
• In Confession. Mortal: must be confessed, each one by kind and roughly how many times (CCC 1456; Code of Canon Law, can. 988). Venial: optional but strongly recommended (CCC 1458).
• Communion. Mortal: go to Confession before receiving (CCC 1385). Venial: you can receive, and Communion itself wipes venial sins away (CCC 1394).
• If left unrepented. Mortal: if it is never repented, it means separation from God forever (CCC 1861; see does mortal sin send you to hell). Venial: no such break, but deliberate venial sins left alone make mortal sin easier over time (CCC 1863).

Examples: the same kind of act, different weight

Many sins can be venial or mortal depending on how serious the matter is. A few common pairs:

• Lying. A white lie to avoid an awkward moment is usually venial. A lie that seriously harms someone, like lying to get a coworker fired, can be mortal (CCC 2484).
• Anger. Snapping at your kids is venial. Anger that becomes a deliberate wish to kill or seriously hurt someone is mortal (CCC 2302).
• Stealing. Pocketing a pen from work is light matter. Stealing a large sum, or cheating someone out of wages they need, is grave.
• Missing Mass. Staying home because you're sick isn't a sin at all. Skipping Sunday Mass on purpose, with no serious reason, is grave matter (CCC 2181).
• Impure thoughts. A thought that pops into your head and is pushed away is a temptation, not a sin. Deliberately dwelling on it with desire is grave matter (Matthew 5:28).

For fuller lists, see the list of mortal sins and the venial sins list.

The gray areas

Real life is rarely as neat as a chart. The question that usually decides it is whether knowledge and consent were really there, and several things can weaken them:

• Habit and compulsion. A deeply rooted habit, or something that has the grip of an addiction, can reduce your responsibility (CCC 1735, 2352). It doesn't make the act good, and you should still work against it, but it may not be fully free.
• Fear, pressure and strong emotion. Panic, duress or a sudden surge of anger can lessen how freely you chose (CCC 1735, 1860).
• Not knowing. If you honestly didn't know something was seriously wrong, and the ignorance wasn't your own fault, your guilt is reduced or removed (CCC 1860). Once you know, though, you're responsible from then on.
• Half-awake or half-aware. Thoughts and reactions that come while you're drowsy, or before you've had a chance to think, aren't fully deliberate.

The Catechism also reminds us that we can judge an act grave in itself, but must leave the judgment of persons to God (CCC 1861). That includes yourself. Can a habit of small sins slide into something mortal? Sometimes, yes; we explain how in can a venial sin become mortal.

What should I do if I'm not sure whether a sin was mortal?

1. Ask the three questions honestly. Was the matter grave? Did I know it was seriously wrong? Did I freely choose it? If you can clearly answer yes to all three, treat it as mortal.
2. Make an act of contrition now. Tell God you're sorry because you love him, and that you'll confess. You don't have to wait to turn back (CCC 1452).
3. Bring it to Confession as it is. You can say, "I did this, and I'm not sure whether I fully consented." That's an honest confession, and the priest can help you see it clearly.
4. If you're unsure about Communion, ask. The rule is to confess first when you're aware of a grave sin (CCC 1385). When you honestly can't tell, Confession first is the safe path, and a quick word with a priest settles it. If you struggle with scrupulosity, follow your confessor's guidance about receiving.
5. If doubts never let up, look at scrupulosity. Constant worry that everything might be mortal is a burden God doesn't ask you to carry. Read about scrupulosity and tell your confessor.

Why the distinction helps

Knowing the difference keeps you from shrugging off something serious, and from treating every sharp word as a disaster. Most of what you notice on an ordinary evening is venial. It needs steady, patient work, and a quick "I'm sorry, Lord" before you sleep. If something clearly serious stands out, look up your parish's next confession time tonight.