If one is in the state if mortal sin and receives the Eucharist knowingly he sins again. Does he also sin with presumption?

The sin of presumption is the sin of presuming that God will forgive you if you commit a sin in the future. So, for example, a person who chooses to commit adultery and thinks, “I’ll just go to confession afterwards” commits the sin of adultery and the sin of presumption of God’s mercy.

Receiving communion in a state of mortal sin is the sin of sacrilege, but not necessarily the sin of presumption, unless one knows that sacrilege is a sin and just plans on confessing it at a later date.

Is not every sin a sin of presumption, though? I mean… if you had no access to confession and would necessarily condemn yourself for eternity by this act, then you probably wouldn’t commit it, right?

Yes, if the person also believed that no matter what, God would forgive Him anyways. Salvation is not assured. Presumption is to believe that for whatever reason we are saved or will be saved no matter what sins we commit.

Anyways, to receive Communion in a state of mortal sin with full knowledge and deliberate consent is a very grave sin and one should seek the Sacrament of Reconciliation as soon as possible, if this did happen.

I don’t think so. Say you wanted to marry someone who was divorced with no annulment. It’s gravely wrong. You’re going to freely choose to it, and suppose you know that the Church teaches it’s wrong and that it offends God. Maybe you just don’t care. Maybe you rationalize that your love for this person is more important than some old Church rules. You have no plans to confess it. I think this would be a case in which you would sin without the presumption of God’s mercy.

Yeah, I thought of a category after I posted it where it wouldn’t be the case. Such category would entail people leaving the faith because they can’t accept the sinfulness of some potential act they want to commit.

But for those of us who are not going to do that, I do suspect there will always be an aspect of presumption if we freely choose to commit the sin. Rather than a case of presumption being there or not being there, it’s merely a matter of degree.

The only way for presumption to not be present is, as you say, a person wants to commit the sin so badly that they are willing to sever their connection to the Church over it, and the Church’s position on it causes them to lose faith for whatever reasons.

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