[Question]{.underline}: Do persons who arrive late for Mass every Sunday commit a sin?
[Answer]{.underline}: Many lukewarm Catholics ignore the two aspects of their Sunday obligation. The first is to be present physically from the beginning until the end of Mass. The second is to assist at Mass with attention, that is in a prayerful manner. Persons who deliberately and through their own fault fail in either of these elements do not fully satisfy their Sunday obligation.
The theologians agree that a person who misses a substantial part of the Mass through his own fault commits a mortal sin, and that if it is a lesser part of the Mass it is only a venial sin, but it is still sinful if it is culpable, through negligence or deliberation. It is considered a substantial part of the Mass if a person arrives after the Offertory, whereas it is considered a lesser part if he arrives at any time up until the Offertory. In such a case, the person ought to wait for the next mass, if there is one, and assist at the part of the second Mass that he missed at the first Mass. Clearly, anybody can arrive late once in a while simply because he is not well organized. However, a person who regularly every Sunday arrives late, cannot be excused of culpability, and furthermore, he gives grave scandal to his fellow parishioners. How, indeed, can somebody rush into church off the street, enter Mass when it is well advanced, and then truly be recollected to pray and offer it as he ought? Such a practice rapidly engenders indifference to sacred and holy things.
Answered by Father Peter Scott, SSPX.