Mortal sin
sinful act which can lead to damnation if a person does not repent of the sin before death
A mortal sin (Latin: peccātum mortāle) is, in Christian theology, a gravely sinful act that leads to damnation if a person does not repent before death. It is also referred to as a deadly, grave, or serious sin. The concept is found in both Catholicism and Lutheranism. In Catholic theology, a mortal sin separates a person from God's saving grace. Three conditions must be met for a sin to be considered mortal: the act must involve "grave matter", be committed with "full knowledge", and be performed with "full and deliberate consent".
Examples of grave matter often relate to violations of the Ten Commandments. Common pastoral examples include getting drunk, engaging in unlawful sexual activity, stealing a substantial amount of property, or deliberately missing mass on Sunday or Holy Days of Obligation. The "sin against the Holy Spirit" and the "sins that cry to Heaven for vengeance" are also regarded as especially serious. According to Denis O'Callaghan, a Catholic priest, mortal sin can be understood not only as an action but as a state of separation from God. Bill Cosgrove, another priest, similarly notes that sin involves a person's goals and priorities, not only individual acts.
This brief starts where responsible research should: with the source description of “Mortal sin” as sinful act which can lead to damnation if a person does not repent of the sin before death. Everything that follows is an evidence route, not borrowed authority.
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Named sources, stable identifiers and responsible institutions provide the strongest route from overview to verifiable evidence. The source revision retrieved here is dated Aug 20, 2026. The linked authority identifier is Q2321540. The Library of Congress control number is sh85122773. 1 of 1 selected statements include explicit references; 0 carry qualifiers and 0 use preferred rank.
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This entry incorporates text from “Mortal sin” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.