Yes, I meant grave matter. sorry
It can be easy to mix “grave sin” and “grave matter” up …especially when your typing them out
This is one way I explain things:
Mortal sin, Serious sin, Grave sin
The Church uses these terms in two senses (and objective if you will and a subjective). And in both senses the terms grave sin, mortal sin, and serious sin are interchangeable.
Here are the two senses:
- Objective sense
Murder is a grave sin.
Murder is a serious sin.
Murder is a mortal sin.
(all three mean the same)
this is one way the Church use the term. Talking about the ‘moral object’ of the act or the ‘objective kind of sin’. Referring to the object itself. Like if I said…do not commit murder for that is a mortal sin.
Then there is this way…
- Subjective sense…
I *committed *the grave sin of Murder
I
committed the serious sin of Murder
I *committed *the mortal sin of Murder
(all three mean the same)
This is speaking of when the thing I committed is grave matter …done with full knowledge and deliberate (complete) consent.
Both are true. Both are ways the terms get used in Church documents
When speaking with someone as to what a mortal (etc) sin is…that is when it is committed. I prefer to use the language of “grave matter”. But it is still true that the thing itself can be said to be “a mortal sin” in the sense that murder is a mortal sin in itself…
objectively.
Ordinarily I tell people “such and such is a grave matter” for mortal sin and if one does it with full knowledge and complete consent…then one commits a mortal sin.