How can the Church make missing Mass such a serious sin?
November 1, 2020, 12:00 PM
The Church did not arbitrarily determine how serious a sin it is to miss Sunday Mass, nor did she invent confession and its necessity – God did. The Church is simply presenting these truths, clarifying them for us, and acting accordingly in her pastoral care for souls. The Church can do this because Jesus gave it His authority – and with it, the promise of the Holy Spirit’s guidance when it teaches on faith and morals (see Mt 16:19, 18:18, 28:20; CCC 553, 874, among others).

Here is an analogy that may help you understand why Jesus established His teaching and governing authority in a visible Church here on earth:

In 1787, the Founding Fathers of the United States did not simply draw up the Constitution and send a message out to the entire country to “go and figure out what the Constitution means for yourself – and decide for yourself when you are breaking the law.” Such a move would have led to disorder, even chaos. Instead, in the same Constitution, they established a Supreme Court to have the final say in interpreting and applying disputed laws. Without this kind of authority structure in place, America would not have lasted very long as a nation.

In a similar (though infinitely more profound) way, Jesus did not just leave us a Book of His laws. Rather, He left us an organized Church with the authority to apply His teaching, including those in the Book (i.e., the Bible), to the lives of His followers. He set aside twelve apostles to lead the Church (see Jn 15:16, 20:21, Lk 22:29-30) and placed St. Peter, the first Bishop of Rome, as their head, giving him the “keys” of the kingdom (Mt 16:19). (In the Bible, keys = ultimate delegated authority; see Is 22:22.)

As the Church grew, the apostles appointed bishops to replace them, who likewise appointed successors, continuing down to the bishops of today. St. Peter’s God-given authority as the Vicar of Christ has been passed down to Pope [Francis], the [266th] bishop of Rome.

The doctrinal authority of the Church (exercised by the bishops united with the pope or by the pope teaching alone) is known as the Magisterium, which safeguards the deposit of faith found in Sacred Scripture and Sacred Tradition (see CCC 86, 95, 100). Without the Magisterium in place, the Church would not have lasted very long. It would have split into major factions (or even new types of “churches”) every time a major theological conflict arose.

Just as the U.S. Supreme Court gives us a final word when interpreting the Constitution, the Magisterium has the final word in interpreting matters of faith and morals. Unlike the Supreme Court, though, the Magisterium has a divine guarantee that it will be preserved from error when it teaches about faith and morals (see Mt 16:16-19; Jn 14:25-26; CCC 890-891).

In light of the earliest traditions in Christian worship, the Magisterium has always taught that Sunday Mass is essential for Christian life and necessary for the fulfillment of the third commandment, the breaking of which is a grave sin requiring a good sacramental confession. This is why the Church can profess the truth about the importance of going to Mass – and the spiritual penalty for ignoring this fundamental command of God.