Is Missing Mass on Sunday a Mortal Sin?
Q. A catechist has told her students it is not a mortal sin if you don’t go to Mass on Sunday. Is it or isn’t it? They were having a discussion of the Ten Commandments.
A. Here’s a reply from Father Reginald Martin:
“For a sin to be mortal,” the Catechism of the Catholic Church states, “three conditions must together be met”: grave matter, committed with full knowledge of the act’s gravity, and deliberate consent (see No. 1857). “It presupposes knowledge of the sinful character of the act, of its opposition to God’s law. It also implies consent sufficiently deliberate to be a personal choice” (No. 1859). If any of these conditions is lacking, an act cannot be mortally sinful. Likewise, if a person commits a sinful action with contempt, or the desire to lead others from the path of virtue, the gravity of the sinful act is increased.
The Ten Commandments and the Precepts of the Church unequivocally express a Catholic’s obligation to attend Mass on Sunday; deliberately to ignore the obligation is a serious matter. However, many things might mitigate this seriousness in individual cases. Poor health, family obligations and difficulty in getting to Mass considerably lessen the obligation, and thus reduce the seriousness of failing to attend Mass.
Determining the seriousness of particular acts demands sensitivity and prudence. We must examine our motives carefully, and confessors “must … conscientiously examine the objective facts and the subjective state of the penitent” (“Fundamentals of Catholic Dogma,” by Ludwig Ott).