For many non-Catholic Christians interested in Catholicism, the Catholic distinction between mortal and venial sin can be a stumbling block. To many such people a sin is a sin is a sin. Fretting over the relative gravity of different sins seems counterproductive. What is necessary is an outright condemnation of sin, not a careful categorization of it.
Furthermore, many people, including many sincere Catholics, struggle with the idea that missing Mass is a mortal sin. If you are going to categorize sins, how is it possible that missing Mass falls into the same category as rape and murder and not the same category as petty theft or thoughtless insults? It is difficult to see how missing Mass could be so damaging to oneself and others as to warrant such a categorization.
It seems to me that much of the confusion here lies in the fact that when we speak about sin in the abstract we almost always consider it objectively, but when we speak about it in the concrete we must always consider the acting person’s subjectivity first and foremost.
Well-catechized Catholics know that there are three requirements for a sin to be mortal. First, there must be grave matter involved; second, there must be full knowledge that the matter is, in fact, grave; and third, there must be full consent of the will. The first requirement is objective, the next two, subjective.
When we say, as is common, that missing Mass is a mortal sin, we are only saying that it meets the first criteria. It would be more accurate (and cumbersome) to say that, due to its gravity, missing Mass has the potential to be a mortal sin. Very few people, even among the most self-consciously orthodox, actually believe that the vast majority of Catholics who missed Mass last Sunday are in a state of mortal sin by that very fact.
Indeed, it is even possible that people who miss Mass do not sin even venially should they have absolutely no knowledge or absolutely no freedom. We find here a strange inversion of our normal way of talking: what is “objectively” sin may not be real sin at all, but only what is “subjectively” sin is, in reality, sin. Real sin, like real love, requires knowledge and freedom. It requires subjectivity.
If we reverse the order of our requirements, putting gravity in the last place, we can catch a glimpse of the real difference between mortal and venial sin. A venial sin is something that, even done with full knowledge and full consent, cannot be used to completely reject God. Someone looking to break their relationship with God would have to be considered half-hearted in their attempt if they tried to do it by stealing a gumball or muttering some small calumny under their breath. In fact, the person would know that they weren’t really trying because they would know that the matter was not grave.
A mortal sin is any act which, when done with full knowledge and consent, can be used to break off one’s relationship with God. Under such a rubric it is much easier to see how missing Mass could be a mortal sin. Because Mass is where we renew our communion with God, someone could use such an omission precisely to break that communion. It is not a matter of missing Mass always being as harmful to oneself and others as murder or rape. It is a matter of the potential way in which missing Mass could be used to say something definitive about one’s relationship with God.
The category of mortal sin does not exist to indicate some tipping point between less and more serious sins, as would be the case if only its first requirement was relevant. Rather, it exists as an affirmation that our actions have the ability to manifest our relationship with God, something upon which the New Testament is insistent. It says that there are things we can do to deliberately break communion. And the category of venial sin indicates that such things take some effort.
Brett Salkeld is a doctoral student in theology at Regis College in Toronto. He is a father of two (so far) and husband of one.