EWTN Catholic Q&A
Mortal Sin
Question from Virginia Cannalongo on 05-14-2001:

I have always been confused by the Catholic Church's injunction that missing mass is a mortal sin requiring the Sacrament of Reconciliation before receiving communion. I do not understand why it is ranked the same as murder, slander, or other grave sin. In my own life, it kept me from receiving communion, and thus not having the graces of the Lord's physical presence, His direct guidance, and the actual experience of His love. I think that I would have maintained my deep love of the Lord, and grown more spiritually connected to Him if I could have received communion without confession for this sin. Why is missing mass a mortal sin?

Answer by Fr.Stephen F. Torraco on 05-14-2001:

Deliberately failing to make one's Sunday or holy day obligation is a grave evil precisely because of the One who is unjustly treated thereby, namely God himself, whom we owe our worship.