Mortal Sins

Bible verse: There is such a thing as deadly sin....Mortal sins are sins of serious or grave matter. “Mortal” means death; they are sins that cause death to the soul. Mortal sins completely sever one’s relationship with God and the sacrament of Penance and Reconciliation (commonly called Confession) is necessary to restore this relationship. Venial sins are less serious sins.

Scriptures tells us that there are sins that are deadly and sins that are not deadly in 1 John 5:16-17.

“If anyone sees his brother sinning, if the sin is not deadly, he should pray to God and he will give him life. This is only for those whose sin is not deadly. There is such a thing as deadly sin, about which I do not say that you should pray. All wrongdoing is sin, but there is sin that is not deadly.”

Conditions for Mortal Sins

Three conditions must be met to classify a sin as a mortal sin. All three of these conditions must be met otherwise the sin is considered a venial sin.

  • Grave matter.
  • Sufficiently full knowledge.
  • Full consent or freedom.

Grave matter means that the sin must be of substantial significance. The Church uses Mark 10:19 as its guideline for what defines grave matter. “You shall not kill; you shall not commit adultery; you shall not steal; you shall not bear false witness; you shall not defraud; honor your father and your mother.” The Catechism of the Catholic Church instructs that “The gravity of sins is more or less great: murder is graver than theft. One must also take into account who is wronged: violence against parents is in itself graver than violence against a stranger.” (Paragraph 1858)

Sufficiently full knowledge means that one must fully know that the sin they are committing is serious and have the intention of breaking the relationship with God. Pretending not to know that the sin is wrong or having a hardness of heart actually magnify that the sin was a personal choice.

Full consent or freedom means that the person must fully and willingly commit the sin. If the person is being coerced to commit the act then it is not a mortal sin. It must be a choice made completely of one’s own free will, a conscious choice. This kind of choice is available to us through God’s gift of free will. God’s desire is for us to love him and making a conscious choice to commit mortal sins is the opposite of loving God.

Mortal sin deprives the soul of sanctifying grace. It kills one’s receptivity to that grace hence the reason it is important to go to confession to cleanse the soul of mortal sins.

The Unforgiveable Sin

The only sin that cannot be forgiven is blasphemy against the Holy Spirit (Mk 3:29; cf. Mt 12:31; Lk 12:10). Blasphemy against the Holy Spirit is the final and obdurate rejection of God’s forgiveness itself, stubbornly refusing forever to accept God’s outpouring of forgiveness.


  1. Cris says

    I am in a state of confusion. Maybe someone can PLEASE tell me what is right. I was previously married in 1996 in my home. I know this isn’t right, but, I do not know the religious back ground of the person who married us. My husband thought he was a minister. I’m not sure what that means. I have since remarried in a church, but not a Catholic church. Actually, I remarried the same man I previously married. My dilemma is does the church recognize my first marriage? I’ve recently returned to the church and am receiving the sacraments. Now I’m in a panic because I’ve read that it’s a mortal sin if I receive communion and was divorced.

  2. says

    I have a friend that’s is from another religion. And keeps telling me about how the Catholic religion. I meet my boyfriend 2 in a half years ago and he’s a catholic and I have been going with him to the catholic church and I like it. But my best friend keeps telling me that the catholics believe in saints and I should believe in saints just our god Jesus christ . but I tell her that I do believe in our god and Jesus Christ our savor. I just can’t get her off my back about the saints.

    • Dan says

      I think it’s time to part ways with your friend and look for some talks by Scott Hahn on the Internet. He was a very anti-Catholic person later converted to Catholicism.

  3. says

    As I read through all the vital comments and arguments on the catholic faith of Purgatory and the death of the Christ on the cross, it gives me a mixed feelings. however, as a catholic I would like to share my view to all denominations; no matter what denominations we are in, to go to haven the only way through is non other than through JESUS CHRIST, HE IS THE WAY THE TRUTH AND THE LIFE(John 14.6). when it comes to purgatory and Death on the cross, we were sinners before we were born,we are sinners today thus, Jesus suffering on the cross was to cleanse us from our past sins intending for us to be God abiding citizens through God’s Commandments after his death. However, in our every day life no body is capable of escaping sinful acts of all nature, thus we are sinning every moment everywhere; Hence, God is a just and MERCIFUL God and haven is for holy people only so how can one enter haven if he continues to sin after Jesus Suffering on the cross, all of us need to suffer the consequences based on the magnitude of our own sin prior to entering the holy place. Thus I believe, there is a PURGATORY existing.

  4. Barb Koetter says

    I would like to know the Catholic stand on:
    Having a civil divorce and living with a person of the opposite sex in a physical relationship. May a person in these circumstances, receive the sacraments?
    Thank you in advance for your time and response.

    • Fer says

      Hi Barb, your question is currently being debated by the synod of bishops in Rome, and they are weighing the official stance on allowing divorced Catholics to receive the Eucharist. Here is a discussion of the topic:

      As you read the official position, please keep in mind that the Eucharist is food for the hungry, not the worthy. Remember, “I am not worthy you that you should enter under my roof, but only say the word and my soul shall be healed”

      May God bless you!

  5. scott Vine says

    Half my family is Catholic and Half are Baptist, but when both faiths get down to the basics of salvation then we both accept our Lord Jesus Christ as our Lord and Savior. We both have a true love for God and Jesus, and accept him as our personal savior, so we both have salvation through Jesus Christ. Catholic, Baptist, Methodist, Protestant and Non Denomination, all have the Love for Jesus Christ and acceptance of him as the Son of God and our Lord and Savior. We shall all share eternity together as one BIG family.

    • says

      Why are there different denominations with different teachings on baptism, grace, and salvation if we are all the same? I’m not trying to cause division, but rather to point out that there are very real differences that cannot be minimized. However, in an ecumenical spirit, I think it is helpful to start by finding the common ground and work from there. Peace.

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