Full Knowledge and the Mortal Sin of Heresy

[thistle]

Everybody would like to say they’ve never done something they know is a sin, but that’s not true of anybody. We’ve all sinned.

You are not able to pass such a judgement on anyone.
Sadly in making your statement that “we’ve all sinned” you are declaring, for example, that Mary sinned which, of course, is not true.
Please take care when making general comments.

Let’s try to clear this up for you.

To commit a mortal sin three conditions must be satisfied.

1. Grave matter
2. Full knowledge (knowing the Church considers the sin to be of grave matter)
3. Full consent of the will (deliberately committing the sin knowing it is of grave matter)

If all three are not satisfied then what you do would not be a mortal sin.

On the other hand if you commit an act you know is a sin and is actually a sin of venial matter but at the time you thought it to be of grave matter and went ahead and committed the sin, the first condition (grave matter) would be satisfied and you would have committed a mortal sin.

As I and others have said talk to your priest who will clarify matters for you.

Remember, though, that to reject/deny or have an obstinate doubt about any infallible Church teaching is not only a sin of grave matter but it is also heresy.