I understand that there are 3 conditions for mortal sin.
1st condition - grave matter
2nd condition - sufficient knowledge
To fulfill the second condition, is it enough to know that the act is sinful, or do you have to know and understand the gravity of the act.
An example would be where someone is aware that it is a sin to miss mass, but is unaware of the gravity of the sin. i.e. that it is a mortal sin.
In this case, would it be a mortal sin?