BuddhistCatholicContemplativeEvangelicalGeneral ChristianHinduJewishLatter-day SaintMuslimNew VisionsProgressive Christian
Beliefs
- Buddhist
- Catholic
- Contemplative
- Evangelical
- General Christian
- Hindu
- Jewish
- Latter-day Saint
- More Voices
- Muslim
- New Visions
- Pagan
- Progressive Christian
Topics
- Religion News
- Food and Religion
- Sports and Religion
- Religious Art
- Religious Music and Entertainment
- Religious Events
- History and Religion
- Style and Religion
- Politics and Religion
- Women in Religion
- Recreation Outdoors and Religion
- Business Finance and Religion
- Careers Workplace and Religion
- Education and Religion
- Family Parenting and Religion
- Health Fitness and Religion
- Home and Religion
- Relationships and Religion
- Technology and Religion
- Travel and Religion
Columnists
- Buddhist Columnists
- Business Finance and Religion Columnists
- Careers Workplace and Religion Columnists
- Catholic Columnists
- Contemplative Columnists
- Education and Religion Columnists
- Evangelists Columnists
- Family Parenting and Religion Columnists
- General Christian Columnists
- Health Fitness and Religion Columnists
- Hindu Columnists
- History and Religion Columnists
- Home and Religion Columnists
- Jewish Columnists
- More Voices Columnists
- Latter Day Columnists
- Muslim Columnists
- New Visions Columnists
- Nonreligious Columnists
- Pagan Columnists
- Politics and Religion Columnists
- Progressive Columnists
- Recreation Outdoors and Religion Columnists
- Relationships and Religion Columnists
- Religion News Columnists
- Religious Art Columnists
- Religious Events Columnists
- Religious Music and Entertainment Columnists
- Sports and Religion Columnists
- Style and Religion Columnists
- Technology and Religion Columnists
- Travel and Religion Columnists
- Women in Religion Columnists
Resource Library
- 2026 Calendar
- Library of World Religions
- The 100 Most Holy Places on Earth
- Patheos Answers
- Podcasts
- Videos
- Faith Leaders Database
- Anglican Episcopalian
- Bahai
- Baptist
- Buddhism
- Christianity
- Confucianism
- Eastern Orthodoxy
- Hinduism
- Holiness and Pentecostal
- ISKCON
- Islam
- Judaism
- Lutheran
- Methodist
- The Church of Jesus Christ of Latter-day Saints
- New Age
- Paganism
- Presbytarian and Reformed
- Protestantism
- Religion Behind the Scenes
- Roman Catholic
- Scientology
- Shia Islam
- Sikhism
- Sufism
- Sunni Islam
- Taoism
- Zen
- See all religions
Research Tools
Ad-Free & Subscriber Log-In Subscription Support
Ad-Free & Subscriber Log-In Subscription Support
- Trending:
- Forgiveness
- |
- Marriage
- |
- Consciousness
- |
- Death Penalty
- |
- Election
- |
- Halloween
- Home
- Catholic
- Politics and Religion
- What Is Mortal Sin?
What Is Mortal Sin?
Last updated on: June 10, 2024 at 1:16 am by Fr. Nicholas Sheehy, LC
What Is Mortal Sin? 2024-06-09T16:16:25-07:00 Fr. Nicholas Sheehy, LC
Patheos Explore the world's faith through different perspectives on religion and spirituality! Patheos has the views of the prevalent religions and spiritualities of the world.
Mortal sin is deadly sin. When we look at what sin is, we recognize that it is a transgression against God’s law. Sin damages relationships between people. It affects our relationship with the natural world. It affects our relationship with God negatively. Ultimately, sin leads to death as it is a rebellion against God. In Catholic moral theology, we distinguish between venial and mortal sin. While venial sin weakens our relationship to God, deadly sin kills this relationship. Mortal sin is a serious offense against God that results in extinguishing sanctifying grace within our soul. This may sound dramatic, because it is.

Mortal Sin is our greatest enemy
Facing Reality of Sin
“Reality cannot be ignored except at a price; and the longer the ignorance is persisted in, the higher and more terrible becomes the price that must be paid” (Aldous Huxley).
We tend to want to hide from the reality of sin. We talk about it in such a way that it loses its gravity. We want sin to be a remnant from a medieval way of looking at the world that has become archaic and irrelevant. Sin is, however, very real, and we ignore it to our peril.
Qualities of Mortal Sin
Within Catholic moral theology, we distinguish between mortal and venial sin. Both of these categories of sin refer to offenses against God. One type of sin injures our relationship with God, while the other is deadly, or mortal. What makes a sin mortal? There are three criteria.
For a sin to be mortal, three conditions must together be met: “Mortal sin is sin whose object is grave matter and which is also committed with full knowledge and deliberate consent.” (cf. Catechism of the Catholic Church, 1857).
Mortal Sin Requires Grave matter
For a sin to be considered mortal, it must be a serious offense against God. Murder is grave matter, as is adultery or fornication. There is a serious offense against God’s law involved in grave matter that is one of the conditions of mortal sin. The sinner is turning his or her back against God.
Full Knowledge
The person committing the sin must know that what he or she is doing is gravely sinful. Thus, when somebody has been far from the sacraments for years or even decades, they may need help to recognize the gravity of some of their actions. Many people may not realize it, but we have a grave obligation to keep Sunday holy by attending Mass.
Full Consent
It is not enough to be intellectually aware of the sinfulness of the act. We must consent to it freely and fully. We cannot be coerced into mortal sin, because if we are coerced, our will is not fully engaged.
So in order to commit mortal sin, we have to do something gravely wrong, know it, and do it willingly anyways. It is a sad reality that we do fall into this type of sin, which is proof of the reality of our free will. We can choose to oppose God, even though obviously this makes no sense.
Mortal Sin and Spiritual Life
Mortal sin sets us back in our spiritual life growth, since we kill the sanctifying grace that has been growing in our souls. We become unable to gain merit, since without sanctifying grace, even our good works do nothing to gain credit for Heaven.
When we sin mortally, we separate ourselves from God. What is the place where we suffer separation from God? Hell is the final destination if we die in such a state. Sin is serious business. So is there no hope?
God’s Redeeming Grace
The good news in the midst of such a terrible topic is that God’s grace is much greater. Through his sacrifice on the cross, Jesus gains the grace we need to be freed from sin. He takes upon himself the punishment that we deserve. He dies in our stead, and by so doing, frees us from sin and from death. To receive this grace, we have the sacrament of baptism. Baptism wipes away original sin and personal sin.
If we have the disgrace to fall into deadly sin after having received the sacrament of Baptism, the sacrament of Reconciliation allows us to go to the seat of God’s mercy and be cleansed of our new personal sin. For this reason, we should always be authentic and sincere when seeking his grace in this sacrament. Mortal sin is deadly sin. This is a sad reality. However, we can be cheered by the fact that God’s love is so great that he reaches down into the depths of despair we prepare for ourselves to rescue us and pull us out. We sin, but he saves.
Subscribe to the newsletter to never miss an article.
History and Religion
About Fr. Nicholas Sheehy, LC
Fr. Nicholas Sheehy was ordained a Catholic priest in 2013 for the Legionaries of Christ. He has been involved in youth work including missions, retreats and apostolic outreach in Germany, Italy, the United States and Central America. He is passionate about the New Evangelization and formation for young adults and married couples. He is a spiritual director and retreat director, offering marriage preparation and marriage counseling through the Divine Mercy Clinic and Family Center. He is currently Executive Director and Chaplain of the Newman Center at St. Philip the Apostle Parish in Pasadena, California. You can read more about the author here.
Previous Post

June 7, 2024
The Devil, Division, and Us
Next Post

June 13, 2024 Called to Grow: Jesus and the Mystery of the Kingdom of God
Recent Comments
"Peace is a precious resource. Humankind and Planet Earth are thirsting for peace. Long live ..."
The Man Who Taught Nagasaki to ..."
"Searching and finding truth and traveling from truth to Truth is an exciting journey. The ..."
Your Writing Makes the Pope Happy
"Rich or poor, we are all fellow pilgrims enthusiastically marching together to our cherished destination. ..."
"There's no moral difference between avoiding conception by using 'artificial' contraception and using a 'natural' ..."
Browse Our Archives
Select a Category Church News Education Eucharist Faith and Mental Health Family Living the Faith Marriage Relationships Spiritual Direction Uncategorized Vocations Women Young Adults
Select a Month October 2026 September 2026 August 2026 July 2026 June 2026 November 2025 October 2025 September 2025 August 2025 July 2025 May 2025 April 2025 March 2025 February 2025 January 2025 December 2024 November 2024 October 2024 September 2024 August 2024 July 2024 June 2024 May 2024 April 2024 March 2024 February 2024 January 2024 December 2023 November 2023
Follow Us!
TAKE THE
Religious Wisdom Quiz
Who was turned into a pillar of salt?
Select your answer to see how you score.
Lot's wife Naomi Lot Ruth
Related posts from Formation Matters
The Big Opportunity for Bishops After the SSPX...
Let Freedom Ring: Truth and the American Soul
Beyond Left and Right: Catholic Church on Immigration
TRENDING AT PATHEOS Catholic
How to Make a Decision When You Can't...
Main point: It’s much more valuable to stay close to God so...
Archdiocese Hosts Military Marriage Retreat in Germany
RASTATT, Germany — The transient military lifestyle, with its frequent deployments and...
Nearly every morning, I make the drive to Detroit with my high-school-age...
The Real AI Story Is Adoption Without Trust
Artificial intelligence has crossed a political threshold. It is no longer a...
A new article, written by Jeff Lindsay and Gale L. Pooley,...
Swimfan: Forgotten Aughts Pleasures
This is a recovery effort. In 2002, My Big Fat Greek Wedding...
view all Catholic blogs
What Are Your Thoughts?leave a comment
Ad-Free & Subscriber Log-In Subscription Support
- About Us
- 2026 Calendar
- Videos
- Podcasts
- Library of World Religions
- Faith In Media Tracker
- Advertise With Us
- Write for Us
- Privacy Policy
- Terms of Service
- Do Not Sell My Data
- Contact Us
- Radiant Digital
- Manage Newsletter Subscriptions
- Unsubscribe From Notifications
- Sitemap
Copyright 2008-2026, Patheos. All rights reserved.
Subscription Support Ad-Free & Subscriber Log-In











