The Church norm of Sunday Mass attendance is based on the divine norm of “Keep holy the Lord’s day”. But for Catholics the Mass is a mysterious recollection of the event that has saved us from sin. It is mysterious in that we are not really recollecting the Passion, Death and Resurrection of Jesus Christ, but actually witnessing it. God is not caught up in time like us and He is willing to share this Mystery with us in a very intimate way. In a world of distractions, many people do not take the time to develop this sensitivity. Sometimes God chooses not to grant a recognizable feeling of this intimacy. Even for those who do experience it, they do not get this feeling every time they go to Mass.
Because the experience of God in the Mass is at times hidden to us, the Church, which is guided by the Holy Spirit, finds it necessary to make a law keep us close to the love of God. The Sunday obligation protects God’s mandate of keeping holy the Lord’s day. It also keeps the presence of the mystery of salvation in our hearts.
Mass attendance is a serious obligation — even to the point of possibly incurring a mortal sin. Thus excusing reasons are not to be taken lightly. In principle one can miss Sunday Mass without committing a mortal sin if one has a grave reason. For example, for the sake of charity if one must take care of someone who is sick and there is no one to relieve that person from this duty, then no sin would be incurred in missing Sunday Mass. One is obliged to do whatever one can to change their situation so that they can attend Sunday Mass. Generally hotels and motels keep a list of Mass schedules for the local churches at the front desk. To answer the more direct question of whether or not one incurs a mortal sin if one misses Sunday Mass, it is best to examine the problem on a case by case basis with a priest in confession.
Fr. Vincent Euk