What is mortal sin?

What is mortal sin and what is the difference between it and “regular” sin?

The Catholic church teaches that there are two types of sin, mortal and venial, mortal is sin leading to hell, and venial, which is sin not sufficient for hell but can still lead to mortal.
1st John, chapter 5 verse 16-17- “If anyone sees his brother committing what is not a mortal sin, he will ask and God will give him life for those whose sin is not mortal. There is sin which is mortal. I do not say that one is to pray for that. All wrongdoing is sin, but there is sin which is not mortal.”

James 1:14-15 also tells us that “each person is tempted when he is lured and enticed by his own desire. Then desire conceives and brings forth sin, and when sin reaches maturity it gives birth to death.” St. James here is also making a distinction between beginning sin and mature sin, which brings death.

mortal sin has to meet three requirements. 1. has to be of grave matter. 2. you have to have know it’s wrong. 3. you have to of your own free will choose to do it anyway.

Venial Sin, in and of itself, will not send you to hell. But like little pin pricks, if you have enough of them, they will stain your soul enough, where eventually they can lead you to hell.


Mortal Sin KILLS your soul Venial Sin harms it. Mortal Sin is a group of sins that the Church believes to kill your soul henceforth damming you to hell.

The common way of looking at salvation is to view it as a matter of what we have done, and what has been forgiven. If we commit a sin, we are guilty and go to Hell. If we confess, we have it wiped off our record and go to Heaven. This view works for a general understanding and everyday conversation, but it falls short when it comes to what is actually happening.

We are born in original sin. This means we are without God’s Grace. When we get baptized, we receive God’s Grace. Baptism puts us in a State of being in and with God’s Grace. We call this being in a state of Grace. We don’t go to Hell or Heaven based on what we have done, but based on whether we are in a state of Grace or not. Because of our sin, we can never be fit for Heaven. Even being forgiven in the way people usually understand it wouldn’t do us any good. You see, having a “clean slate,” as we usually think of it, doesn’t matter because we are by our very nature corrupt and impure, and as we know nothing impure can enter into Heaven. The common way of looking at Baptism is that it “washes away” original sin. In one sense this is true, because it alone Christ makes us able to receive God’s Grace and be in a State of Grace. However, even Baptism leaves behind an impurity which we call concupiscence. Concupiscence is a “disordered nature,” a nature which is not natural and not according to God’s design for us. In “laymen’s” terms, it is an attachment to sin: something that makes us “want” to sin. Concupiscence is an impurity. Because of that, even being forgiven doesn’t really cut it if we want to get to Heaven.

ONLY through God’s Grace may we make it to Heaven. God’s Grace gives us that free gift of Salvation that nothing can earn. When we are God’s Grace, He promises to bring us to Heaven even though we don’t deserve it. This is truly Grace indeed! Therefore, through God’s Grace, he gives to us Purgatory: a purification to remove the impurities in our souls, such as concupiscence.

Sin also has two ways of looking at it: the common way and the technical way. The common way to look at sin is to look at it as breaking some sort of law or rule, like “do not commit adultery.” The technical way to view sin is as a rejection of God’s Grace. The original sin of Adam was something very simple: rejecting God and going against Him. This is what all sin is in its essence. Killing is not a sin because it is intrinsically wrong, but because it is a rejection of God’s commandment and therefore truly a rejection of God Himself (which is essentially why God Himself can take lives without sinning). God can’t sin not because He is so powerful and righteous (though He is), but because sin is nothing more or less than the rejection of God. Put another way, a sin is something which falls short of loving God.

Venial sins are those acts which don’t completely reject God. They are “minor” things which fall short of loving God, but don’t actually reject Him. A mortal sin is a sin which at its core rejects God. This is why a mortal sin has its three qualifications: grave matter, full knowledge, and full will. To reject God, a person must know it is God he is rejecting, and also must have the want. This is why for a Christian, only mortal sin can send a person to Hell. When we are in God’s Grace, we will be purified and goto Heaven. Only rejecting this Grace and becoming Graceless will condemn us because if we don’t reject God’s Grace it will save us. An unbaptized person never was in a state of Grace in the first place, so it doesn’t matter if they have full knowledge or will when they commit sin. They may not go to Hell, but without the Grace to be purified they can’t make it to Heaven (When they Church talks about people outside its visible boundaries being saved, it is assumed that they have received a Baptism of Desire).

A mortal sin, therefore, is an act which completely and utterly rejects God and therefore His Grace which alone would save a person. A venial sin is an act which is not completely in line with loving God but doesn’t reject Him. Think of parents and a teenager. If a teenager lies and tells his parents that he did his homework when he didn’t, this is not completely living up to the idea of loving them, but it certainly doesn’t reject them. If the teenager sneaks out in the middle of the night, he is completely missing the goal of loving them and he rejects them.

When we completely miss the goal of loving God, this is mortal sin. Therefore, when a person denies God exists, this completely misses the goal of loving God. It is a rejection of Him. When a person kills, it completely falls short of loving God. When a person tells a white lie, or steals a dollar, it doesn’t completely fall short of loving God, but it doesn’t completely live up to it. This is a venial sin.



No amount of venial sins will ever send a person to Hell, because they never put a person out of God’s Grace. They never outright reject God’s Grace. However, it is important to remember that God’s Grace enables us and helps us to avoid sin. It helps us to love God more. Therefore, every time a person commits a venial sin, its an act which by its vey nature is a refusal to cooperate with God’s Grace. The person doesn’t reject the Grace, but he chooses not to cooperate with it. When a person commits venial sin after venial sin after venial sin, he chooses to not cooperate with the Grace again and again and again, and he gets used to not using the Grace. This leads to a person being very likely to utterly reject God’s Grace. Thus, commiting many venial sins leads to mortal sin. Mortal sin is a rejection of God’s Grace, which is the only thing that can purify a person and allow them to enter Heaven. This is what St. James is refering to in James 1:14-15:

“Then after desire has conceived, it gives birth to sin, and when sin is fully grown, it gives birth to death.”

A person’s desires are his concupiscence. When James speaks about the birth of sin, he is referring to venial sins: minor acts that fall short of the goal of loving God. Fully grown sin is mortal sin: acts which completely reject God and completely miss the goal of loving Him. These, of course, give birth to death: damnation. This also ties in very closely to Jesus’ statement that the greatest commandment is to love God with all your heart, and all your mind, and all your soul. This is the greatest commandment because it’s really what life is about and what actually matters. Nothing else really means anything, because everything at its core breaks down to either loving God or not loving God.

I could go on and on about this, but I hope this helps…

All sin is a loss or rejection of Gods grace. In Catholic teaching there is a destinction between Venial and Mortal sins. Mortal sins are sins that are basically a complete rejection of God’s grace. They are serious acts done with free will and full knowledge of what is being done and the consequences. An example would be murder or theft.

A venial sin is a sin that, while it is against God, is not a turning from God’s grace. It is an act that you may know is wrong, but it may be out of habit. An example may be a small lie that does not hurt anyone. It is still a lie though and is a sin, but it might be done out of habit.

Mortal sins, without true contrition, send a person to hell because they are a complete rejection of the grace of God. Venial sins, while they will not send you to hell, will certainly lead you in that direction due to the attachment they cause in a person. They will cause a person to become attached to sin and it can destroy a persons spiritual life. A venial sin is not a complete rejection of God though like mortal sin.

I would stay away from statements like “if you get enough venial sins you will go to hell”. That is not an accurate understanding of sin. They don’t add up. It isn’t like if you tell 500 small lies you will go to hell. It is more based on the perfection of your soul in the likeness of Christ. We are to become like Christ. Venial sin will corrupt us and lead us away from Christ. Our job is to free ourselves from sin and corruption, or atleast to try, sin hinders that process.

Lazerlike42, that is a good explanation of sin. I would just like to add that through baptism, we recieve grace. Technically it is not the wiping away of Original Sin(Original Sin is just the lack of Grace or Justice or Holyness), but the filling with grace. I think you implied this, but I just wanted to complete the idea that sin is nothing but a rejection or the lack of subjection to God. Sin is not some material thing.

[quote=jimmy]Lazerlike42, that is a good explanation of sin. I would just like to add that through baptism, we recieve grace. Technically it is not the wiping away of Original Sin(Original Sin is just the lack of Grace or Justice or Holyness), but the filling with grace. I think you implied this, but I just wanted to complete the idea that sin is nothing but a rejection or the lack of subjection to God. Sin is not some material thing.

I was going to add that but I was having trouble wording it in a way that wouldn’t seem confusing so I left it out :slight_smile:

So… who decides if sin is mortal or not?

[quote=BluegrassJimmie]So… who decides if sin is mortal or not?


[quote=BluegrassJimmie]So… who decides if sin is mortal or not?

It’s not a matter of who decides whether a sin as mortal or not. It’s a matter of whether or not a sin is an act which completely misses the point, completely misses God. In society, we have felonies and misdemeanors. They’re all crimes, but the government labels some crimes as felonies, which have a harsher penalty, and some as misdemeanors, which have a lesser penalty. It’s about what the sin does to the relationship between God the sinner, not about whether the sin is “labeled” as mortal or venial. This could be different things for different people. For two people, the same act could be two different kinds of sins, even though the nature of the act is the same. This may seem confusing, so here is a practical, everyday way of understanding it and thinking about it:

Mortal sin requires 3 things: Grave matter, full knowledge, and full will.

Grave matter, in other words, means a sin has to be a “big deal,” which means it is very opposed to God. We know if something is very opposed to God because of His fundamental commandments. These commandments can be though of as rules in everyday life, but in reality they are just God’s telling us what He is, what He “likes.” God’s greatest commandments are to love God, and to love your neighbor. Anything that really completely misses the point of these two things is grave matter. Worshipping an idol completely misses loving God. Killing a person completely misses loving a neighbor, and since the neighbor is the image of God, it completely misses loving God. Adultery, premarital sex, masturbation, stealing a large sum, and other things of this sort completely miss loving God. That is grave matter.

Full knowledge means that a person knows what he is doing is very wrong and misses the point of loving God/neighbor. If a person doesn’t know something is against God, then by doing it he can’t be rejecting God, and he can’t be rejecting God’s Grace.

Full will means you have to be fully in control and want to do it. If a person is going to reject God, he has to really mean to. When we are baptized, we are put in a state of Grace. A person who is in a state of Grace HAS to get out of that state to miss Heaven. Otherwise, the Grace will save him. One can only get out of God’s Grace by rejecting it. That’s why you need full will. A person can’t reject something without meaning to. A sin which doesn’t have full will doesn’t reject God’s Grace because the intent isn’t there.

Now, you have to understand something very, very important. This does NOT mean that a person can go around killing or having premarital sex or anything else and just say, “oh I am doing this but I’m not rejecting God.” This is where full will, the 3rd requirement, and full knowledge, the 2nd, go together like peanut butter and jelly. When a person has the knowledge that something is a sin (that it misses the point of loving God) and they choose to do it, they are choosing to reject God. It is not enough to avoid rejecting God Himself. A person only has to do something which he has the knoweldge to know is a rejection of God. When a person knows something is very much against God, he knows that doing that thing is a rejection of God, because rejecting God is not about literally deciding against God, but is about not loving Him. If we do something against Him, we are not loving Him, which is what sin is.

This begs the question: why don’t we just make sure nobody ever learns about God so nobody can sin? The answer lies in the very definition of sin: anything which misses the point of loving God. If we love God, we will always try to learn about Him, and to do as he says (see John 14:15). If we know about God, but refuse to learn about Him, we are mortally sinning because we are knowingly and willingly not loving God as much as we can.

Therefore, in your everyday life, think about it like this. A mortal sin is a sin which is a “big deal” (some say one which violates the 10 commandments, but there are a few things that are big deals which aren’t in the 10 commandments, like premarital sex), which a person knows is wrong, and which a person does intentionally. Anything that meets this requirement is a mortal sin. Also, remember that in a certain way it is a mortal sin to deliberately avoid learning what else are sins, because it meets all three: it’s a big deal, it is done knowing there is more to learn, and it is done intentionally.

Let me rephrase: is there a listing in scripture of what God has decided are mortal sins?

[quote=BluegrassJimmie]Let me rephrase: is there a listing in scripture of what God has decided are mortal sins?

No. Like I said, in our society there is a listing of what is a felony and what is a misdemeanor. These things are either felonies or misdemeanors because some lawmaker said they were so. Sins aren’t categorized. Sins are NOT simple violations of rules. They are very simply any acts which fall short of loving God. Any act which completely misses the goal of loving God is a mortal sin. Because they aren’t violations of rules, they aren’t listed anywhere.

You can’t just list them because mortal sins are different for different people. If Ed knows premarital sex is wrong and he does it, he is sinning mortally. If Jane doesn’t know it is wrong, she isn’t sinning mortally. That’s one way they can be different. The more important way is expressed in the story of Jesus and the rich man, where Jesus tells him to sell all he has. To this man, being rich was a mortal sin because it kept him from loving God completely. The man loved his money so much he couldn’t love God. We saw this because he refused to give up the money for God. To me, being rich might not be a mortal sin, because I may be able to love God while being rich. If I can be rich but be willing and ready to give it up at any time for God if I needed to, it wouldn’t be a mortal sin. That’s why we can’t just make a list. Something as simple as playing a video game, which would not be sinful for most people, may be a mortal sin for a person if it kept that person from loving God. Very simply anything that keeps you from loving God is a mortal sin.

You can’t put together a list of mortal sins, but you can put together a list of grave matter. Remember that acts which are of grave matter (“big deals”) are the ones which CAN become mortal sins if they are done with knowledge and will. Here’s a list I am coming up with right now:

premarital sex
stealing large value
not going to mass
killing a person
taking revenge on a person
bearing false witness against someone
lusting after a person
Misuing God’s name (like using Him to justify something wrong)
homosexual acts
beating up a person
breaking an oath to God

There are more. Like I said, something that to every other person on earth isn’t sinful might be to you if that thing keeps you from loving God. Also remember that the things on this list are only mortal sin if a person knows they are wrong and does them intentionally.

Doesn’t this then become kind of subjective? As in, open to our interpretations?

There is sin which is mortal …
1John 5:16

But as for the cowardly, the faithless, the polluted, as for murderers, fornicators, sorcerers, idolaters, and all liars, their lot shall be in the lake that burns with fire and sulphur, which is the second death."
Rev 21:8

…nor did they repent of their murders or their sorceries or their immorality or their thefts.
Rev. 9:21

Do not be deceived; neither the immoral, nor idolaters, nor adulterers, nor sexual perverts, nor thieves, nor the greedy, nor drunkards, nor revilers, nor robbers will inherit the kingdom of God.
1Cor. 6:9-10

Now the works of the flesh are plain: fornication, impurity, licentiousness, idolatry, sorcery, enmity, strife, jealousy, anger, selfishness, dissension, party spirit, envy, drunkenness, carousing, and the like. I warn you, as I warned you before, that those who do such things shall not inherit the kingdom of God.
Gal. 5:19-21

…you know that no murderer has eternal life abiding in him.
1 John 3:15

[quote=BluegrassJimmie]Doesn’t this then become kind of subjective? As in, open to our interpretations?


There are so many levels to this, but I will talk about the most basic one.

Sin is the act of failing to love God. God has told us that loving Him means keeping His commandments. Jesus told us all sorts of things we must do and all sorts of things we mustn’t do. Also, throughout the OT God conveyed His message of what we morally ought and ought not do. (Of course things like animal sacrifices don’t fall into this category because they are ceremonial, and abolished with Christ, and so doing them no longer has anything to do with loving God or following His commandments). Keeping these moral commandments is the act of loving God.

Therefore, even in Scripture we have all sorts of things we are told to do (like helping the needy) and told not to do (like murder). These are very objective.

[quote=BluegrassJimmie]Doesn’t this then become kind of subjective? As in, open to our interpretations?

No. Christ established his church so that we could know what constitutes moral behavior. God did not leave us adrift in this fallen world with our defective consciences as the only guide to truth.

Many Protestants believe that their conscience is the ultimate arbiter of truth, but that is Protestant heresy. The Catholic Church has always rejected the “mistaken notion of autonomy of conscience”. **Catechism of the Catholic Church

1792** Ignorance of Christ and his Gospel, bad example given by others, enslavement to one’s passions, assertion of a mistaken notion of autonomy of conscience, rejection of the Church’s authority and her teaching, lack of conversion and of charity: these can be at the source of errors of judgment in moral conduct.Since Christ’s church cannot teach error in matters of morality, it is impossible to possess a perfect conscience that is in conflict with what Christ’s church teaches. If one disagree with what the Catholic Church teaches about morality, that is only proof of one thing – that one has a defective conscience that is in need of formation.

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