Three Conditions of a Mortal Sin?

Hi you guys, I just wanted to ask something specific about the three conditions. I’ve been struggling to try and understand this for a while, so yeah here it goes. It says on the Catholic handout that my spiritual director gave me, that one of the conditions of a mortal sin is that it has to be a serious matter. And it goes on in depth by saying that “The thought, word, action, or omission must be seriously wrong or believed to be”. The thing that gets me is the line “believed to be”. Is that line specifically talking about the individual who has committed the sin, that if that individual believes that it is serious, even though she/he doesn’t really know whether or not that the Church believes it to be a mortal sin; that it still meets that condition?

And my other question is that is it still considered that that condition has been met even if you’ve only realized that it was serious “after” you committed the sin ?

~ Thank you guys ahead of time and God Bless!

I see your dilemma. I think the “believed to be” is more than just a personal belief. It means that the Church is general believes it to be serious. I like to teach my students that a mortal sin is 1. involving grave matter (Serious with a capital S); 2. the person committing the sin knows it is wrong, and 3. the person freely chooses to do it anyway.

We all need to form our consciences on the teachings of the church.

What the OP is addressing would be something different. It is referring to the person themselves.

I always thought the “believed to be” part had to do with the fact even if you don’t accept the Church’s teaching but you still do something against the teachings it is wrong. Like birth control. Even if you feel it is morally ok, the church says no so it is a sin if you do it. :confused:

What the OP is addressing would be something different. It is referring to the person themselves.

But yes most certainly we need to form our conscience according to the Teaching of the Church.

Such there is dealing the an erroneous judgment.

Where a person judges in error that Y is a grave matter --and then with full knowledge gives deliberate consent. The grave matter here is basically the “willing to commit mortal sin”.

Now let me quickly note that there are readers out there who struggle with scrupulosity --they are to have a “regular confessor” to guide them. For they tend to see mortal sin where it is not etc. They can be in a different boat for they can have the direction of their confessor or say principles he has given them to follow. So they should not scruple here but turn rather to their regular confessor etc.

As to the last question there - if say I honestly have not clue that Y is a grave matter --and I do it judging it is good --but find out later that I was wrong and it is a grave matter. It just never occurred to me that such could be so…

Such would be where one* did not have the needed knowledge* -but indeed acted in good faith. Thus the three aspects for mortal sin would not be present.

(now of course many things we know via natural law --and we do not even need to know the term mortal sin in order to commit such --like for example most would know murder is rather bad…)

Hope that helps.

It may help to read the Catechism of the Catholic Church (CCC). Below is a snippet, but I would suggest reading the whole section (it isn’t too long).

1857 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.”131

1858 Grave matter is specified by the Ten Commandments, corresponding to the answer of Jesus to the rich young man: “Do not kill, Do not commit adultery, Do not steal, Do not bear false witness, Do not defraud, Honor your father and your mother.”132 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. (2072, 2214)

1859 Mortal sin requires full knowledge and complete consent. It presupposes knowledge of the sinful character of the act, of its opposition to God’s law. It also implies a consent sufficiently deliberate to be a personal choice. Feigned ignorance and hardness of heart133 do not diminish, but rather increase, the voluntary character of a sin. Source:

I hope this helps?


Thank you guys for the help, it really help me out :slight_smile:

taking over a bit
what about computer use
i sometimes feel god is telling me it’s wrong and i shouldn’t do it
but i do it anyway

is this a mortal sin.

What if a young girl living at home with non christian parents and is expected to sleep with her boyfriend (obviously outside marriage)…I have seen that a lot in modern society. … and the pressure on her to conform is such that it is absolutely not normal to wait until your married. If later the girl decides after getting married or in marriage preparation that she decides to be a Christian and raise her children as Christians would her previous sin be mortal or is the responsibility on her parents who are married yet teach behaviour that is against the marriage sacrament? This is quite common in britain that people are getting married after having their children (in Protestant churches)…my point is…sorry im rambling. …is it like Abraham leaving his pagan upbringing and not responsible for his upbringing and starting afresh? Would the young girl need to confess to a Priest or would confession be relevant at start of christian fairh…so if then she practised fornification that would be mortal as she has turned away from a conscious knowledge of the truth as an adult?

Since she is a non-Christian she would receive baptism- and none of this would then exist. She would be a new creation.

Nothing to confess -even if there where 1000 mortal sins. For it would all be washed away in baptism and would not even be matter for confession.

She would repent, believe in Jesus of Nazareth and be baptized…and then confirmed and receive Jesus in Holy Communion…(of course all this after RCIA usually…) Then when she makes her first confession–* none* of the prior baptism sins (even if they were mortal due to knowing via natural law etc) would be confessed…for she repented and they where washed away in baptism.

If you have been baptised very young. …im talking about a Protestant baptism and then no further instruction as the parents dont attend church normally (im not saying all protestants are like that) and there follows the amoral upbringing. After being in a Protestant church say faithfully ,married,active Christian and raising children in a proper Christian environment…so a proper turning around of a life…would that young girl have to confess again mortal sin even though as a young girl she was under the moulding and instruction of non practising christians? The reason I am stressing this point is that if you become a christian in a protestant church (I mean a genuine commitment and belief)you have a completely different view point regarding mortal sin.if someone after being a christian for a fair while and has had repentant life would her previous mortal sins need to be confessed. …ie were they mortal as she was under resonsibility of bad upbringing and baptised as a young child.would on entering the Catholic faith would she have to start again? Or is mortal sin appropiate from the time zhe becomes catholic. I think this is a good question for long term practising protestant christians considering the Catholic faith?

Ok a new very different person.

Can a person commit a mortal sin who has never heard the term “mortal sin”? Yes. A person does not need to know the term or the detailed theological reality of mortal sin in order to commit a mortal sin - much can be known via natural moral law etc. A person can commit a mortal sin via say murder or adultery …and not know it is called a “mortal sin” or know the theology. Paul is quite clear in his letters that Gentles too sinned seriously…(and did good acts too…)

But is it possible that a person is invincibly ignorant (that is they have no clue it seriously wrong and did not know they should know such–and they believe it is ok or good even) and not commit a mortal sin though the matter was grave matter? yes.

If it was a valid baptism – one would examine ones conscience prior to confession. One would need to confess all mortal sins. Now if there is doubt at to if it was mortal at the time – it is advisable to confess them anyhow - noting however that there is such doubt.


1860 Unintentional ignorance can diminish or even remove the imputability of a grave offense. But no one is deemed to be ignorant of the principles of the moral law, which are written in the conscience of every man…

Catechism on Natural Law:


Compendium issued by Pope Benedict XVI

  1. In what does the natural moral law consist?


The natural law which is inscribed by the Creator on the heart of every person consists in a participation in the wisdom and the goodness of God. It expresses that original moral sense which enables one to discern by reason the good and the bad. It is universal and immutable and determines the basis of the duties and fundamental rights of the person as well as those of the human community and civil law.

  1. Is such a law perceived by everyone?


Because of sin the natural law is not always perceived nor is it recognized by everyone with equal clarity and immediacy.

Remember a protestant/evangelical church, after baptism there isnt first communion and reconciliation as there is in the Catholic church. So a protestant who comes to the church (protestant)as an adult would repent in private not with a Priest in confession. So this is a stumbling block for protestant christians who are considering the Catholic faith. Its not for me but some people struggle with going over confessed sins before they were christians.

They would not have to confess a single sin from before they were Christians. That is prior to Baptism.

And as for post-baptismal mortal sins -that were mortal – once one realized the reality of the Catholic Church …of the Sacraments-- all this falls into place-(as it did for me)–and one wants very very much to go to Confession (as did I).

Im not questioning with deciphering what is mortal and what isn’t I suppose. …I.m not explaining very well am I !..its the fact that a genuine christian in the protestant church to transfer to the Catholic faith would they have to confess previously confessed sin both mortal and venial if they have been repentant genuinely because it has not been confessed to a Priest in the protestant church.

Yes–if they were mortal sins -and done after a valid baptism - they will need to confess such in the Sacrament --for they have not been yet confessed the way Jesus wills to normally happen (via the Sacrament of Confession)…and they will come to see that this is the case and desire to do that very thing.

They before did not know this -they thought they were doing what needed to be done in the case of post-baptismal serious sins – but now they will come to realize this and will wonderfully experience the wonderful Sacrament. Where they will encounter in a wonderful way the love of Jesus.

(venial sins would not need to be confessed…though such rather recommended …at least regularly. They can be forgiven in various ways…prayer etc.).

Thankyou for that because im trying to be confession didnt cover pre protestant church life so I have a gap. I need to go to confession.

(PS: note too that mortal sin needs to be confessed in number and kind -adultery 3x…but if one does not recall from ones examine how many times -one may approximate according to what one recalls).

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