Catholic hamartiology is a branch of Catholic thought that studies sin. According to the Catholic Church, sin is an "utterance, deed, or desire",Catechism of the Catholic Church (CCC) 1849 caused by concupiscence,CCC 1849 that offends God, reason, truth, and conscience.CCC 1849 The church believes sin is the greatest evil and has the worst consequences for the sinner (original sin and damnation), the world (human misery and environmental destruction), and the Catholic Church itself (Passion of Jesus and wounds to the church's unity).CCC 1488 Based on the Bible, the Catholic Church distinguishes between two kinds of sins: mortal sin and venial sin.CCC 1854 The Catholic Church also distinguishes between the state of being in original sin and the commission of actual sin.CCC 405
Official teaching The Catechism of the Catholic Church details most aspects of the church's official teaching on sin and forgiveness.
Reality of sin The reality of sin is one of the arguments of divine revelation, e.g., sin is present in historyCCC 386 and divine revelation sheds light on it.CCC 387
Nature of sin Sin is an "utterance, deed, or desire" that offends God, reason, truth, and conscience. It is caused by concupiscence. Sin is the greatest evil and has the worst consequences for the sinner, the world, and the church.CCC 387
Misunderstanding of sin Without divine revelation, sin can be misconstrued as "a developmental flaw, a psychological weakness, a mistake, or the necessary consequence of an inadequate social structure, etc."CCC 387
The call to reject sin The church's baptismal liturgy asks members to affirm that they "reject sin, so as to live in the freedom of the children of God".Sacred Heart Catholic Church, Ilkley, Baptismal Promises, accessed on 27 July 2025 The Second Vatican Council noted that during Lent,
God permits, but does not will, evil God, in his goodness, only wills good.CCC 294 He permits evil for the sake of a greater good.CCC 312 This is evidenced by the Paschal mystery: God permitted his Son to suffer and die for the sake of mankind's redemption.CCC 312
Who can sin? Angels and humans are capable of committing sin because, unlike every other creature, they have free-will.CCC 391 However, children who have not reached the Age of Reason are not accountable for their sins.Code of Canon Law, can. 97 §2 A mental illness may also prevent a sinner from having full knowledge and consent, thus reducing or eliminating culpability.Code of Canon Law, can. 1859
No double predestination No creature is predestined to commit sin or go to hell.CCC 1037
Fall of angels and humans The angels and first humans underwent a test of love of God at the beginning of time; some angels sinned and became demons, then tempted the first humans to sin as well.CCC 391
Creation of hell By falling from heaven, demons gave rise to the existence of hell.Compendium of the Catechism of the Catholic Church, Q. 74... they rejected God and his Kingdom, thus giving rise to the existence of hell
Demons are tempters Out of envy, demons tempt humans to commit sin.CCC 392
All sinners are to blame for the Passion of Jesus Every human who sins is an author and minister of the Passion of Jesus.CCC 598
Reign of sin The reign or regime of sin in the world is not arbitrary or a conspiracy; rather, it is each person's struggle against his or her own concupiscence.CCC 1606
Disorder of sin The regime of sin causes disorder, which can be "more or less overcome according to the circumstances of cultures, eras, and individuals".CCC 1606
Defeat of and end to sin Sin's reign is temporary, beginning with the fall of the angels and ending in definitive defeat with the crucifixion of Jesus.CCC 613 Every human can share in Jesus' eternal reign on the wood of the cross via the sacraments.CCC 618 At the end of the world, sin will no longer exist nor be possible ever again, because Jesus' eternal reign will then be absolute:CCC 1060 he will be everything to everyone,CCC 1130 i.e., fulfill everyone's every desire.
Actual sin Actual sin is the commitment of a sin. The first actual sin in history caused humanity to lose the state of original holiness, which included sanctifying grace.
State of original sin After the fall, every human—apart from the Immaculate Conception—is now conceived in the state of original sin.CCC 416
Kinds of actual sin There are two types of actual sin: mortal and venial.CCC 1854
Mortal sin Mortal sin is a deliberate sin of grave matter, such as murder.CCC 1857
Eternal punishment Mortal sin entails eternal punishment since it destroys sanctifying grace.CCC 1861
Grave matter according to the Decalogue The church does not have a full list of every possible sin. However, the Catechism of the Catholic Church does list certain offenses against the Ten Commandments that constitute grave matter.CCC 1858 They include: 1st Commandment: superstition, idolatry, polytheism, divination, magic or sorcery, irreligion, atheism, tempting God, sacrilege, simony, heresy, schism, apostasy.CCC First Commandment 2nd Commandment: abuse of God's name, magical use of God's name, committing sin or crime in the name of God, blasphemy, false promises, false oaths, perjury, insult.CCC Second Commandment 3rd Commandment: skipping Mass without grave reason (sickness, giving birth, etc.), impeding the worship of God, hindering the observation of Sunday, unnecessary demands.CCC Third Commandment 4th Commandment: the state of refusing to assist and protect the family, violation of human rights, disobedience to parents or authority, ingratitude to the church, refusal to disobey evil, negligence of children.CCC Fourth Commandment 5th Commandment: deliberate destruction of human life, deliberate killing of the innocent, capital punishment, intentional homicide, direct abortion, direct euthanasia, suicide, scandal, cult of the body, every kind of excess (drug abuse, overeating, etc.), inhumane scientific experiments, inhumane research, kidnapping, hostage taking, terrorism, torture, non-therapeutic and medical sterilization, non-therapeutic and medical amputation, non-therapeutic and medical mutilation, disrespect to the dead, unjust war, war crimes, unregulated production or sale of arms, arms race, economic or social inequality.CCC Fifth Commandment 6th Commandment: lust, masturbation, fornication, pornography, prostitution, rape, sodomy, homosexual acts, marital infidelity, domestic violence, artificial conception, adultery, divorce, polygamy, incest, child abuse, free union, concubinage, cohabitation, trial marriage.CCC Sixth Commandment 7th Commandment: theft, fraud, unjust wages, deliberate retention of lent goods, deliberate retention of lost objects, forcing up prices, unjust contracts, violation of a just contract, refusal to make reparations for injustice, unfair gambling, slavery, disrespect to animals, disrespect to environment, rich nations refusing to help the less fortunate, lay faithful refusing to directly intervene in politics, refusal to aid the poor or needy, human misery (material deprivation, unjust oppression, etc.)CCC Seventh Commandment 8th Commandment: lying, rash judgment, detraction, calumny, satirical caricature, participation in sin, bragging or boasting, violation of professional secrets, violation of the sacramental seal, violation of privacy, iconoclasm.CCC Eighth Commandment 9th Commandment: evil intentions, complicity in impure thoughts, immodesty, moral permissiveness.CCC Ninth Commandment 10th Commandment: greed, envy, desire to amass goods without limit, desire to acquire someone else's property through unjust means, refusal to practice charity.CCC Tenth Commandment
Sins that cry to heaven for justice There are five mortal sins that cry to heaven for justice: the blood of Abel, the sin of the Sodomites, the cry of the Jews oppressed in Egypt, injustice to the wage earner, and the cry of the foreigner, widow, and orphan.CCC 1867
Diminishment of guilt Feelings, passions, pathological desires (such as the psychological wounds of child abuse), or external pressures (such as the threat of death) can diminish the voluntary and free character of a mortal sin. Unintentional ignorance, such as not knowing the gospel, can diminish or even remove the imputability of a mortal sin.CCC 1860
Gravest of sins Sins committing through malice—or deliberate choice of evil—is the gravest.CCC 1860
Unforgivable sin The eternal sin—blasphemy against the Holy Spirit—is the mortal sin of final impenitence, e.g., dying unrepentant, which cannot be forgiven precisely because the sinner refuses to accept forgiveness.Pope John Paul II, Dominum et Vivificantem, 6 Why is blasphemy against the Holy Spirit unforgivable? ...blasphemy against the Holy Spirit consists precisely in the radical refusal to accept this forgiveness,...
Venial Sin Venial sin is a deliberate sin of non-grave matter, such as a white lie, or an accidental sin of grave matter, such as an accidental killing.CCC 1855
Temporary punishment Venial sin entails temporary punishment since it weakens the theological virtue of charity.CCC 1863
Habitual sin A vice is when one is in the habit of committing sin. While it does not deprive someone of sanctifying grace, friendship with God, charity, and eternal happiness, it still opposes virtue.
Seven capital vices There are seven capital vices, commonly mistakenly referred to as the seven deadly sins. They are called "capital vices" because these vices engender sin: pride, avarice, envy, wrath, lust, gluttony, and acedia.CCC 1867
Discrimination The catechism condemns "[e]very form of social or cultural discrimination in fundamental personal rights on the grounds of sex, race, color, social conditions, language, or religion".CCC 1935 Note that the church does not see its inability to ordain women as a discrimination on the grounds of sex, since Jesus himself only ordained men,CCC 1577 and since there is no right to holy orders.CCC 1578
Sins of the church Pope John Paul II made many apologies for the church's sins—including against women, Jews, victims of the Inquisition, and Muslims—throughout its history. Pope Benedict XVI apologized for the clerical sex abuse scandal.NPR, [Pope Benedict XVI apologizes for handling of sexual abuse cases but denies wrongdoing]
Participation in sin Participating in another's sin is grave matter according to the Eighth Commandment. One participates in sin by flattery, adulation, or complaisance;CCC 2480 by taking part in the sin; by ordering, advising, or approving of sin; by not disclosing or hindering sin; or by protecting evildoers.CCC 1868
Forgiveness of sin Only God forgives sinsCCC 1441 because forgiving sins is the height of omnipotenceCCC 277 and forgiveness is the greatest of God's deeds.CCC 1994
Everyone can be forgiven God is not bound by space or time or the church, so those who have no access to the sacraments can still receive divine mercy.CCC 1257
Repentance The only prerequisite for forgiveness is contrition,CCC 1431 (also called repentanceCCC 1492) however this does not include original sin.CCC 1257 While necessary for forgiveness, repentance is nonetheless impossible after death.CCC 393
Sacraments The sacrament of baptism forgives all sins and original sin and grants sanctifying grace,CCC, Baptism the sacrament of confession forgives all sins and restores sanctifying grace,CCC, Confession and the sacrament of the Eucharist forgives all venial sins and augments sanctifying grace.CCC, Eucharist
The church treats the season of Lent as a particular period in the liturgical year when its members and catechumens recall or prepare for their baptism and do penance, before the Easter celebration of the paschal mystery.
Repentance outside confession