Why does mortal sin keep one from Heaven?

I know mortal sin kicks the life of grace out of the soul, but what exactly is it about mortal sins that causes this? A bunch of acts are gravely wrong, but other sinful acts do not constitute *mortal *sins. So why can, for example, adultery and murder keep one from Heaven while saying a little “white lie” won’t? What is it about mortal sins that keep one from going to Heaven?

It seems a bit arbitrary to say that doing certain things keep one from entering Heaven while others do not. What is it about mortal sins that 1.) make them grave and 2.) keep one from Heaven?

Stealing a paper clip is not going to land you in jail…

but stealing a porsche will

some things are…well darn serious…and others are not…

Mortal sin is different in essence…than venial sin…it attack the life in us that is given us in Baptism…just as a bullet through the heart attacks the nature life in us where as a stubbed toe does not …


Often we Catholics will say in defense of hell, for example, that “no one goes there unless they will it.” But how does committing a mortal sin translate into saying “No, God, I don’t want to be with you, I choose hell.” This is what makes me think very few people actually commit mortal sin, since if mortal sin keeps one from Heaven, that sin must be rejecting God. I don’t think many people, when they commit grave sins, are saying “No God I don’t want you,” I think they mostly do so under weakness.

This is why we are not to judge. Committing a mortal sin is choosing hell because the sinner says “What I am doing is seriously wrong and offensive to God,** but I do not care” **

Some things in life destroy a relationship while others do not, why? some things are just more complete turnings. For example, in a marriage, adultery would destroy the relationship. It is a choice to completely turn away from your spouse. Snapping at your spouse would not kill the relationship, it is not as offensive or an open choice to completely turn from your spouse. Just because somebody cheated out of “weakness” does not mean they are not guilty of a serious offense. (NOte: not a perfectanalogy, but the best I could think of off the top of my head)

BTW- I don’t know for sure, but I think a white lie would not be considered a sin because it is culturally understood that this is a polite way of avoiding hurting someone’s feelings (e.g. If somebody has you for dinner and asks you if you like it, they would be hurt if you said no, and do not expect you to say no even if you disslike the meal)

Because they are mortal (or serious, grave, etc.)

Good question, catholic1seeks. To begin with, I think it is important to point out that venial sins can also result in a person going to hell if the person is not repentant.

What is it about mortal sins that 1.) make them grave and 2.) keep one from Heaven?

Naturally, our relationship with God is a relationship of love, and in many ways our experience of God can mirror our experience with one another.
(TomD123 mentioned this in his post, and I will put my own spin on it and maybe elaborate on it a bit further).
Generally speaking, our relationships with one another can exist in three different ways:

1) We are free to love our neighbor completely, which includes treating him like a brother, attending to his wants & needs, and truly allowing him to be part of our lives.

2) We are also free to instead only love our neighbor in a partial way, such as having a casual relationship with him, but not a close one. For example, we may like to talk with him at the neighborhood BBQ and send him a Christmas card each year, but if he needs a favor that inconveniences us (such as needing an early morning ride to the airport) then suddenly we make up excuses as to why we can’t help. Basically, we value his friendship, but not enough to set the alarm for 5:00 a.m. and drive him to his flight.

3) And finally we are free to ignore him completely, acting as if he did not exist. Maybe we never really wanted to know him in the first place, or maybe he was our friend but we decided to completely end the friendship (the result is the same).

In a similar way, we are free to love God completely, only somewhat, or not at all. If we love God but still commit venial sins then our relationship with God may be more casual than close (such as Example #2 above). After all, we have decided that even though we love God, we are unwilling to make certain sacrifices for the sake of that love. Here we may call to mind the attitude expressed by St. Augustine, “Lord, make me pure, but not yet!” But on the other hand, our sinful actions and our attitude have not completely severed our relationship with God (and therefore heaven is still a possibility for us).

But just as we are free to completely ignore our neighbor, or to completely severe a relationship with him, we are free to do this with God. In every loving relationship, each person has certain expectations of what it means to be loved. God has given us what his expectations are, and mortal sin (which is freely and knowingly committed) is the means by which a person can completely and totally reject God. A complete and total rejection of God includes the choice of not being where God dwells, which is heaven. The only alternative place (in terms of one’s ultimate destination) is hell.

According to the Catechism (#1862):
“One commits a venial sin when, in a less serious matter, he does not observe the standard prescribed by moral law, or when he disobeys the moral law in a grave matter, but without full knowledge or complete consent.”

Therefore, if one commits a mortal sin but his knowledge of the situation or freedom to resist was somewhat impaired, his culpability (in the eyes of God) may be lessened. Even though the specific action was (objectively speaking) involving grave matter, God may consider it akin to a venial sin due to other circumstances. In light of this, if we examined your statement about sinning “under weakness” in more detail, it may end up being applicable to what the Catechism is describing in #1862.

But let us also keep in mind the old saying, “Actions speak louder than words." A person may claim that he has a close relationship with God, but his actions may prove otherwise. He may say, “Yes, God I want you” but his actions show a rejection of God and his commandments. Consider this in light of Jesus’ teachings in the Parable of the Sheep and the Goats (Matthew 25:34-46).

By *definition *a mortal sin is a sin that is serious enough to keep someone who is unrepentant from heaven. We all sin. All sin is bad, even venial sins. Venial sins add up, yet Christians won’t go to hell for venial sins–by definition again. We use the terms mortal and venial sins to distinguish which sins are serious enough that they need to be repented of and brought to Jesus through the Sacrament of Confession from other sins that are covered by His grace through other means (like Communion).

If a person knows that some sin is serious enough to keep them apart from God for eternity AND they choose to do it anyway in full knowledge with full consent AND they never repent, then they have demonstrated that they love their sin more than they love God. But while commiting just one mortal sin may keep a person from heaven, please do not make the mistake of assuming that mortal sin will always send a person to hell. Remember the thief next to Jesus on the Cross. Repentance is a beautiful thing! Jesus offers us forgiveness. A mortal sin that has been repented and confessed will not keep a person out of heaven.

I like the way you answered here.

So does this mean that someone is committing a mortal sin and will be kept from Heaven only if that person knows he is doing something that says “No!” to God?

I appreciate your response very much! It was very helpful, and I like the analogies. I’m still having a bit of trouble understanding WHY certain things are mortal–like why they, as you say, “completely severe a relationship.” You also say a mortal sin is “complete and total rejection of God.” How is this so? That’s why I say in my OP that the list of mortal sins seem arbitrary. Of course I will admit it may be hard for us to understand why certain things translate into a “complete rejection of God,” because the answer may just well be “that’s just the way things are” but… I just want to understand! :rolleyes: So I would really like it if you could go further with this!

A mortal sin by definition means a person is rejecting God’s love. A mortal sin cannot be committed by accident. It is a deliberate act of committing a sin known to be of grave matter. By committing a mortal sin a person knows they are deliberately separating themselves from God.

Erich, this is incorrect. Venial sin will NOT result in a person going to Hell, even if it is unrepented. It will result in a very serious spell in purgatory, of course, but not hell. From the CCC:

"1863 Venial sin weakens charity; it manifests a disordered affection for created goods; it impedes the soul’s progress in the exercise of the virtues and the practice of the moral good; it merits temporal punishment. Deliberate and unrepented venial sin disposes us little by little to commit mortal sin. However venial sin does not break the covenant with God. With God’s grace it is humanly reparable.*** “Venial sin does not deprive the sinner of sanctifying grace, friendship with God, charity, and consequently eternal happiness.”*** "

You are absolutely correct.
Hell is the destination of those who die with unrepented mortal sins, not venial sins.

Thank you for pointing this out, Lily. Although I stand by my original statement, I need to clarify it in light of CCC# 1863. Repentance for sin (mortal and venial) is a necessary component for salvation. Otherwise, God would be forcing his mercy on us, and this would contradict the various biblical teachings that we are to offer our contrition to God in order to be open to his forgiveness (such as expressed in Psalm 51:17).

Also let us consider what the Catechism states in its teaching on blasphemy against the Holy Spirit, which is mentioned therein immediately after the quote you provided about venial sin:

There are no limits to the mercy of God, but anyone who deliberately refuses to accept his mercy by repenting, rejects the forgiveness of his sins and the salvation offered by the Holy Spirit. Such hardness of heart can lead to final impenitence and eternal loss. (CCC #1864)

There is no qualification that this specifically applies to mortal sin rather than sin in general. Moreover, the following is Dr. Peter Kreeft’s elaboration on CCC #1864:

“No sin is too great for God’s forgiveness to save us from, but no sin is too small to damn us if we refuse to repent of it.”

  • Dr. Peter Kreeft, Catholic Christianity (Ignatius Press: San Francisco, 2001), 123.

Likewise, in the Catechism’s teaching on 1John 8-9…

To receive his mercy, we must admit our faults. “If we say we have no sin, we deceive ourselves, and the truth is not in us. If we confess our sins, he is faithful and just, and will forgive our sins and cleanse us from all unrighteousness.” (CCC# 1847)

Therefore, a person who is only guilty of venial sins can, indeed, end up in hell if he flat out refuses to be contrite over them. I suppose it could be argued that this refusal to repent constitutes a mortal sin, and that would be an interesting discussion in and of itself. But to keep this in the context of the OP, my initial statement was that even though venial sins are not as serious as mortal sins, our attitude about them (such as refusal to be repentant) can still put us into hell.

Lily, I think that you and I agree on the necessity of repentance, but we differ on when it has to happen (regarding venial sin). Correct me if I’m wrong, but you seem to imply that if a person does not repent of venial sin in this life (and he is not guilty of mortal sin) then he does so in Purgatory. But I submit that it has to happen prior to Purgatory. In other words, it seems that it has to take place prior to one’s particular judgment. Exactly how the time-table for this works out is known only to God, but even if someone never specifically repented of venial sins in his life, it stands to reason that he had better have a contrite heart for all his sins (even venial ones) when standing before the throne of God.

People who go to Purgatory have already been deemed justified in the eyes of God, and everyone who goes to Purgatory will eventually end up in heaven. In light of this, the time for someone’s repentance is before his judgment, not after.

Killing someone may or may not be a mortal sin, even if done deliberately in order to save another preson’s life.

Yes, killing is wrong-- but let’s use an extreme example and say that a “bad guy” is about to kill someone… or is already in the act of killing people like the Arizona shooter. I, as a person trained and skilled in the use of a firearm, happen along the scene and I must make a very fast decision. It’s apparent that the “bad guy” isn’t going to sit down and discuss his act over coffee and donuts like a reasonable person, and I’m also in danger of being killed if I hesitate. The person is already shooting in this scenario, and others are too scared to act. Thus, to save others and myself, I take the chance and (somehow) manage to fatally shoot the “bad guy”.

I have (technically) sinned by killing the “bad guy”, but my intentions were honorable-- saving innocent lives. Thus, I have sinned, but not mortally. God would not judge me as harshly for my actions as He would if I were simply committing a murder. Still, I must confess my action, repent, and perform a penance due to the seriousness of this act. While probably not truly a MORTAL sin, this would be serious enough to warrant sacramental Confession. Of course, I also have a “worldly” (civil or criminal) consequence to face as well in that I would likely have to stand trial in court.

This is different than killing someone in order to rob them, for instance. That would be a mortal sin, of course, as well as a serious crime. My action in the second case would be to harm, not to PREVENT further harm from occurring.


Sorry but that is not correct. If a person dies with only venial sins on their soul they are SAVED.
Only if you die in a state of mortal sin do you go to Hell.
Venial sins do not separate us from God (this is the Church teaching).

Remember that Jesus said "Enter by the narrow gate for the gate is wide and the way is easy that leads to destruction and those who enter by it are many. For the gate is narrow and the way is hard that lead to life and those who find it are few."Mat 7:13

Countless saints have written that more souls will go to hell than to heaven. While the Church has not declared it to be a dogma is has been the teaching of the Church that there are different degrees of punishment in hell. A person that murders many will be punished more than a person that murders one and ignorance is not always a valid excuse. Luke 12:46-48 shows this reality.

Many will be in hell base on the natural law written on their hearts and ignorance may “accuse or excuse” them. Romans 2:15-16
From the Catechism
1801 Conscience can remain in ignorance or make erroneous judgments. Such ignorance and errors are not always free of guilt

1790 A human being must always obey the certain judgment of his conscience. If he were deliberately to act against it, he would condemn himself. Yet it can happen that moral conscience remains in ignorance and makes erroneous judgments about acts to be performed or already committed.

1791 This ignorance can often be imputed to personal responsibility. This is the case when a man “takes little trouble to find out what is true and good, or when conscience is by degrees almost blinded through the habit of committing sin.” In such cases, the **person is culpable **for the evil he commits

1793 If - on the contrary - the ignorance is invincible, or the moral subject is not responsible for his erroneous judgment, the evil committed by the person cannot be imputed to him. It remains no less an evil, a privation, a disorder. One must therefore work to correct the errors of moral conscience

But refusal to repent of them does separate us from God, which has been my point throughout this thread, and which I backed it up with the Catechism. Here it is again:

There are no limits to the mercy of God, but anyone who deliberately refuses to accept his mercy by repenting, rejects the forgiveness of his sins and the salvation offered by the Holy Spirit. Such hardness of heart can lead to final impenitence and eternal loss. (CCC #1864, emphasis added)

Exactly where does the Church teach otherwise?
Where does the Church state that an unrepentant sinner is saved?
If someone dies who is only guilty of venial sins but at his particular judgment he is unrepentant of these sins, are you suggesting that he is still declared justified by God? How can he be when the very attitude of such lack of repentance is clearly a manifestation of the sin of pride?

This is about MORTAL sins, not venial sins!!

Exactly. By your logic, Eric, there is no real difference between mortal and venial sins. What point is there making the distinction if both will equally damn us to Hell if unrepented?

Technically speaking, ALL sin keeps one from Heaven.

It’s just that smaller sins keep you from Heaven temporarily while you are cleansed of them in Purgatory while mortal sins separate you permanently from Heaven in Hell.

It’s kind of like in a friendship when you may find a friend’s behavior hurtful but if the actions are extremely mild you might tolerate it even though you dislike it. But certain actions can be deal-breakers unless there is a true repentance / apology in any relationship. The same is true with God.

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