What is "full knowledge" as it relates to mortal sin?

I have heard some say that it is simply KNOWING that the Church teaches that something is wrong.

I have also heard that it is both KNOWING and BELIEVING that something is wrong.

If it is the first instance, then anyone who has ever heard the teachings of the Catholic Church (even Muslims) would be obligated to follow those teachings under the pain of damnation.

The second definition seems more accurate because for true mortal sin, doesn’t one have to BELIEVE that one is offending God and CHOOSE to do it anyway when GRAVE MATTER is involved? This seems to be the only way one would truly separate themselves from God forever, by doing this and not repenting. If one doesn’t believe that what they are doing is offensive to God, then how could it be a mortal sin?

A Muslim may have heard the Catholic Church teaches such and such but he may have an invincible erroneous conscience and not accept that the Church is the Church of Jesus Christ and thus teaches with his authority etc…and not believe that Jesus is the Son of God etc…

So for them to hear “the Catholic Church teaches such and such is a mortal sin” …may not mean anything for them…

A Catholic however is in certainly a very different boat.

A Catholic IS to believe what the Church Teaches…after all he is a Catholic…

So if he discovers that the Church teaches that x is a mortal sin…well that is how he is to form his conscience…thus now knowing that x is a grave matter and when confronted with X he knows he is to choose to not do X…

If a Muslim comes to know Jesus and his Church…(to realise he is the Son of God etc)…he too would need to follow him in his Church…

Of course some things…are known simply by reason…and in natural law…and even a Muslim can know that such and such is very very bad.

PS: and a Catholic does not have to think “I am offending God” when they commit a mortal sin.

Full knowledge means that one knows that the act is wrong according to natural law or to Church teaching. A person doesn’t have to believe that the teaching is correct.

If I jump off a building, I do not have to truly believe that I am falling. The effect is the same. Splat.

God is more generous than the law of gravity. Gravity does not care if I “know” that I will fall. I just fall. God gives more leniency…he says you are separating yourself from him if you “know” you are falling, if the falling is serious in nature and are falling by choice of the will. Whether or not I truly believe I am wrong in the eyes of God is irrelevant. The consequence of sin is death. People lie to themselves all the time about what is right and wrong (I have). Denial is not a good excuse. Look at an adulterer: He may know that adultery in the abstract is an offense against God. But…he makes excuses. “I need to feel loved. I am in love with someone else. I am trapped in my marriage. Blah blah blah.” He may believe he is not in the wrong, but his “belief” is not a condition upon the violation of God’s commandment. Sin is death.

Also, you become your sin. Sin transforms you into something that just won’t fit in heaven. It changes your humanity into an image of your sin.

Yours in Christ.

PS: If you are talking about yourself and saying that you have committed sin without really believing it was a sin, get to confession. Christ wants you to come home.

Catechism of the Catholic Church paragraph 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.

Please explain in more lament terms. I don’t not understand completely. It may be the reason I can’t attend mass, which leaves me very empty.

I’m am not sure what you mean by more sorrowful terms but the CCC refers to the idea that one would know that the act that one might commit is sinful in nature. The reason that you cannot attend Mass may have nothing to do with this because it must be coupled with complete or full consent. The Catechism is just stating that if one knows the sinfulness of the act (that it goes against the will of God) and then gives full consent to this serious act then the sin would become a mortal of grave sin.

Your individual issue with Mass attendance should be addressed separately and not aligned with a general definition. So please do not let a definition leave you empty. There is much more involved in all of the discernment regarding sin and its gravity. God bless you… teachccd

The criteria is ‘Full Knowledge’, not “Full Knowledge and Belief”.

If belief was in there, it would mean that almost every concentration camp guard during the Holocaust commited no sin.

Many were probably aware that mass extermination of innocent people would be against Catholic teaching, but how many of them actually believed what they were doing was wrong.

The same, perhaps even more so, would be true of other mass murders, such as Stalin’s Famines or Pol Pot’s Cambodia.

How many here are willing to Eichmann or Stalin are in heaven ( and hence Saints) because they didn’t believe what they were doing was wrong.

Full knowledge is when you know. Don’t get sidetracked by the word “full”.
Full knowledge is satisfied by simply knowing the Church teaches something is a sin of grave matter. While it is good if you understand the teaching that is not necessary to satisfy full knowledge. If you do not understand a teaching of course it would make sense to look deeper into it to try to get an understanding.

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