Mortal sin: what it is, the three conditions, and how it is forgiven

What is a mortal sin?

A mortal sin is a serious sin that breaks a person’s friendship with God and the life of grace in the soul. The Catechism defines it as “sin whose object is grave matter and which is also committed with full knowledge and deliberate consent” (CCC 1857). It is called mortal — from the Latin for death — because, left unrepented, it brings death to the divine life we received at Baptism (CCC 1855).

The Church distinguishes mortal sin from lighter, everyday faults, a distinction she finds already in Scripture (CCC 1854). Mortal sin “destroys charity in the heart of man by a grave violation of God’s law”, turning him away from God; a lesser sin wounds our love without breaking it (CCC 1855). Our guide to venial sin explains the difference, and what is sin covers the wider question.

What are the three conditions for a mortal sin?

For a sin to be mortal, three conditions must be met together (CCC 1857). If even one is absent, the sin is serious in another sense but it is not mortal — it is venial. This is why you cannot judge a sin by its outward act alone: the same action can be mortal in one person and not in another, depending on what they knew and freely chose.

Several things can lessen or remove responsibility, so that a grave act is not a mortal sin for this person (CCC 1860, 1735). Unintentional ignorance can diminish or even remove blame. Strong feelings and passions, outside pressure or fear, force of habit, and psychological disorders can all reduce how free and deliberate a choice really was. The Church takes these seriously, which is one reason she leaves the final judgment to God.

The other direction is also true. Pretending not to know, or a hardness of heart that refuses to learn, does not excuse a sin — it makes it worse (CCC 1859). And a sin done out of sheer malice, choosing evil for its own sake, is graver still (CCC 1860). Honesty with yourself, not clever excuses, is what the examination before Confession asks of you.

Is there a list of mortal sins?

There is no single, numbered “mortal sins list” that the Church publishes, because whether a sin is mortal depends on knowledge and consent as well as the act. What the Church does name is the grave matter: the kinds of act serious enough to be mortal sins when the other two conditions are present. Grave matter is specified above all by the Ten Commandments (CCC 1858).

The table below lists grave matter the Catechism names, with the paragraph where it is treated. Read it soberly, not as a verdict: it tells you which acts are serious, not whether any particular person has sinned mortally. Grave matter alone does not make a mortal sin.

Two of these call for a careful word. On the sixth-commandment sins, the Catechism itself says that affective immaturity, the force of acquired habit, conditions of anxiety and other factors can lessen or even extenuate moral responsibility (CCC 2352). On homosexuality, the Church teaches that the persons themselves “must be accepted with respect, compassion, and sensitivity” (CCC 2358). And on suicide, she adds that grave fear and psychological distress can diminish responsibility, and that we should never despair of anyone’s salvation (CCC 2282–2283).

For help turning this into an honest review of your own life, use our examination of conscience and sins to confess. Remember throughout: the list names the matter; only you, before God and with a priest, can weigh the knowledge and consent.

What does the Bible say about grave sin?

Scripture speaks plainly of sins that, unrepented, shut a person out of God’s kingdom. St Paul gives two such lists, and both end not in fear but in hope. He first names “the works of the flesh” and warns the Galatians where they lead.

Writing to the Corinthians he gives a similar list — and then turns it inside out with the word “but”, which is the whole Gospel in miniature: the same people who had done these things have been washed clean.

What happens to the soul in a state of mortal sin?

Mortal sin results in “the loss of charity and the privation of sanctifying grace, that is, of the state of grace” (CCC 1861). It does not end God’s love for the sinner; it refuses, for now, the life of grace that love offers. If it is never redeemed by repentance and God’s forgiveness, and a person persists in it to the very end, it leads to eternal separation from God (CCC 1861, 1037).

That is the truth the Church must tell. But she tells it with the mercy that answers it, and she is careful about what she will not say. The Catechism is explicit: “although we can judge that an act is in itself a grave offense, we must entrust judgment of persons to the justice and mercy of God” (CCC 1861). No one — not a friend, not a stranger online, and not you about yourself — can declare a soul lost. That belongs to God alone.

How is a mortal sin forgiven?

The ordinary way God forgives mortal sin is the Sacrament of Reconciliation, which asks “a new initiative of God’s mercy and a conversion of heart” (CCC 1856). You confess every mortal sin you remember, by kind and roughly how many times (CCC 1456), receive absolution, and rise restored to grace. If you are not sure how, our guide on how to go to Confession gives the words.

What if you are in grave sin and cannot reach a priest soon? Make an act of perfect contrition — sorrow that springs from love of God above all else. Such contrition obtains the forgiveness of mortal sins at once, provided it includes the firm resolution to confess sacramentally as soon as possible (CCC 1452). Sorrow born of fear of judgment is also a true gift of God and is enough to bring to the sacrament (CCC 1453). The traditional Act of Contrition puts it into words.

One practical rule follows from all this. Anyone conscious of a mortal sin “must not receive Holy Communion … without having first received sacramental absolution” (CCC 1457, 1385). So do not go to Communion before Confession; go to Confession first, and then return to the altar with a clear conscience.

How do I know if I have committed a mortal sin?

This is the question that most needs a pastor, not a web page. The grave matter can be named plainly, but full knowledge and deliberate consent are hidden things that only God reads perfectly. If you honestly do not know whether a past act was mortal, the answer is not to agonize but to bring it to Confession and say so simply: the priest will help you weigh it and will not leave you in doubt.

If fear keeps circling back on the same sins, or you feel you can never be sure you have confessed enough, that may be scrupulosity rather than sin; read our guide to scrupulosity and tell your confessor. And if you are frightened that your sin is beyond forgiveness, take heart: no sin brought to God in repentance is unforgivable, as our guide to the unforgivable sin explains.

Sources

Cited by paragraph and verse, so you can read them in full. In the end, your priest has the final word.

• –Catechism of the Catholic Church, 1854–1864
• –Catechism of the Catholic Church, 1735
• –Catechism of the Catholic Church, 1451–1458
• –Catechism of the Catholic Church, 2268, 2271–2272, 2352–2354, 2357, 2380–2381, 2408–2409
• –Catechism of the Catholic Church, 2088–2090, 2120, 2148, 2152, 2181
• –Catechism of the Catholic Church, 2280–2283, 2477–2479
• –Galatians 5:19–21
• –1 Corinthians 6:9–11
• –Code of Canon Law, canons 987–989

Confession Compass is an independent educational tool, not an official body of the Catholic Church. It never absolves sins: only a priest, in the Sacrament of Reconciliation, can absolve.