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Dear visitor: Summer is here, and you may be thinking about a well-deserved vacation, family get-togethers, BBQs with neighborhood friends. More than likely, making a donation to Catholic Answers is not on your radar right now. But this is exactly the time we most need your help. The “summer slowdown” in donations is upon us, but the work of spreading the gospel and explaining and defending the Faith never takes a break. Your gift today will change lives and save souls for Christ this summer! The reward is eternal. Thank you and God bless.

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Why Is It a Mortal Sin to Miss Mass?

In this age of Catholic laxity, many have lost sight of the fact that it is a grave (i.e., mortal) sin to skip Mass on Sunday or a holy day of obligation when one is able to attend. But a glance at the liturgical life of the early Christian generations will show us the depth and urgency of Mass obligation.

For about two hundred and fifty years, from Nero to Constantine (c. 64-312 A.D.), taking part in Eucharistic worship was a crime punishable by death. It is true that official persecution of Christians by the state was intermittent. There were periods when the state was preoccupied with other matters and periods when local authorities simply chose to ignore the Christians’ existence. But always, a Christian’s being apprehended at worship was a capital crime.

During the times when the law against Christian worship was not being enforced, a Christian still might be martyred if someone accused him of being a Christian and he refused to deny it. Hippolytus reports the case of Callistus who brought action to recover payment of a business debt. To avoid paying, his debtors accused Callistus of being a Christian. He was thereupon scourged and condemned to work in the lead mines of Sardinia for the rest of his life. Eusebius tells of a soldier Marinus who was accused of being a Christian by a fellow soldier who envied Marinus’s promotion to centurion. Within three hours after the accusation was made, Marinus was put to death (Gregory Dix, The Shape of the Liturgy [Westminister: Dacre Press, 1947], 145).

According to Dix, the Roman government had little concern about individual Christian believers. It focused its attack on Christians’ expressing their beliefs in corporate worship. When a Christian lapsed under the threat of death, the state probably didn’t care whether or not he was sincere. The state knew that apostasy would exclude that Christian from the assembly. And it was the assembly itself that was always the primary target of persecution.

Ironically, the Church and the state were agreed on one point: the basic test for determining if a person were Christian was whether that person shared regularly in the Church’s worship. For the state, a person who professed Christian beliefs but did not express them in worship posed no danger. For the Church, beliefs not expressed in regular Eucharistic worship were meaningless.

State and Church were at odds, of course, on the significance of public worship. The state regarded sharing in the Christian assembly as an act of treason, a capital crime. The Church regarded sharing in its worship as “the supreme positive affirmation before God of the Christian life” (Dix, 147).

Vatican II repeatedly sounded this latter theme. “The liturgy is the summit toward which the activity of the Church is directed; it is also the fount from which all her power flows. For the goal of apostolic endeavor is that all who are made sons of God by faith and baptism should come together to praise God in the midst of his church, to take part in the Sacrifice and to eat the Lord’s Supper” (Constitution on the Liturgy 10).

Further: “It is the liturgy through which, especially in the divine sacrifice of the Eucharist, ‘the work of our redemption is accomplished,’ and it is through the liturgy, especially, that the faithful are enabled to express in their lives and manifest to others the mystery of Christ and the real nature of the true Church” (ibid. 2).

In focusing its attack on Christian worship, the Roman state struck especially hard at the clergy. It killed great numbers of them or sentenced them to penal servitude for life. It confiscated property that had been used for Christian worship and sought by all possible means to make it impossible for Christians to assemble in worship.

We can hardly imagine the atmospheres of danger in which ordinary Christians regularly risked their lives to share in the Eucharist. St. Cyprian treats as common the practice of smuggling a priest and a deacon into the prisons to celebrate the Eucharist for confessors about to be executed. In another source, we read about an imprisoned priest, Lucian, who, lying on his back, was being slowly torn apart. He celebrated the Eucharist for the last time, using his chest for an altar, and gave Communion to those lying in the darkness around him (Dix, 152).

At the height of the fiercest persecution under Diocletian (303-313), a congregation in Africa had gone into hiding and was being sought by the authorities. After being deprived of the Eucharist for weeks, they summoned a priest to celebrate, saying they could no longer go on without the Eucharist. They knew they would all be apprehended and put to death. And they were.

Those early Christians, ordinary people like us, did not risk their lives continually to go to worship simply to think about what Jesus had done for them. Nor did they regularly take their lives in their hands simply to receive Holy Communion. They could do both these things in the comparative safety of their homes. In earliest centuries, communicants were allowed to take the Blessed Sacrament to their homes and communicate themselves daily. If authorities discovered that a Christian suspect was carrying what we would call a pyx, with the Blessed Sacrament in it, the death sentence was sure to follow quickly.

What impelled those Christians to risk their lives regularly by sharing in the Eucharist?

They were convinced that only in this corporate action could each Christian receive the fulfillment of his being as a member of Christ’s Body. They believed with all their hearts that in the Eucharistic action, “as in no other way,” each person could take his part ” in that act of sacrificial obedience to the will of God which was consummated on Calvary and which had redeemed the world, including himself.”

Ordinary Christians regularly risked their lives by going to worship because they were convinced “there rested on each of the redeemed an absolute necessity so to take his own part in the self-offering of Christ, a necessity more binding even than the instinct of self-preservation. Simply as members of Christ’s Body, the Church, all Christians must do this, and they can do it in no other way than that which was the last command of Jesus to his own” (ibid., 152f.; emphasis added).

Keeping in mind that Dix was an Anglican, not a Catholic, note what he says about the Catholic rule of Mass attendance: “That rule of the absolute obligation upon each of the faithful of presence at Sunday Mass under pain of mortal sin, which seems so mechanical and formalist to the Protestant, is something which was burned into the corporate mind of historic Christendom in the centuries between Nero and Diocletian.”

But, adds Dix, “It rests upon something evangelical and more profound than historical memories. It [the Mass obligation] expresses as nothing else can the whole New Testament doctrine of redemption, of Jesus, God and Man, as the only savior of mankind, who intends to draw all men unto him by his sacrificial and atoning death, and of the church as the communion of redeemed sinners, the Body of Christ, corporately invested with his own mission of salvation to the world” (ibid., 154).

Now for the doctrine underlying the Church’s Mass obligation. Scripture commands us to “work out your own salvation with fear and trembling, for God is at work in you, both to will and to work for his good pleasure” (Phil. 2:13f). A Protestant commentator says this passage means we have been saved, we are being saved, and will finally be saved. Our grave obligation to share in the offering of the holy sacrifice arises out of these facts and especially out of the second: We are being saved.

With regard to the Eucharist, Scripture explains that “as often as you eat this bread and drink the cup, you proclaim the Lord’s death until he comes” (1 Cor. 11:26). The question is, proclaim to whom? The standard Protestant answer is, proclaim to ourselves and to the world. But this is only a by-product of the proclamation intended by Scripture. Our liturgy repeatedly declares that in the Eucharistic offering we are proclaiming the Lord’s death—and all that entails—to God the Father.

Why must we proclaim the Lord’s death to God the Father? Because “when we proclaim the death of the Lord you [God the Father] continue the work of our redemption” (prayer over the gifts, second Sunday in Ordinary Time; emphasis added). The same declaration occurs in another prayer over the gifts (Votive Mass B for the Holy Eucharist): “For whenever this memorial sacrifice is celebrated the work of our redemption is renewed “(emphasis added; this prayer was previously quoted in the second excerpt from the Constitution on the Liturgy, above).

Now we can begin to understand why the Book of Hebrews often exults over the fact that the work of Christ the high priest is going on right now and will continue to the end of time. Unlike the Levitical priests, whose tenure in office was limited to their adult life, Jesus “holds his priesthood permanently, because he continues forever. Consequently he is able for all time to save those who draw near to God through him, since he always lives to make intercession for them” (7:23-25; emphasis added).

Speaking of the will of the Father that the Son came to accomplish, Hebrews explains, “And this will was for us to be holy by the offering of his body made once for all by Jesus Christ” (Heb. 10:10).

The offering made once for all is continually repeated in our behalf by the celebration of the Eucharist, thus continuing the working-out of our redemption. “By virtue of that one single offering, he has achieved the eternal perfection of all whom he is sanctifying.. ” Literally, “for by one offering he has perfected in perpetuity the [ones] being sanctified” (10:14; emphasis added). Note the present progressive tense: the process of sanctifying, the process of applying the benefits of Christ’s redemption to each of us, is going on right now through the Eucharist.

The benefits of the objective redemption of the whole world wrought by Christ have to be applied to each individual in his unique life situation. It is a continual process of application, not a once-for-all-event. Sharing in Eucharistic worship is the primary means whereby we allow the Holy Spirit to work out our salvation in us.

The Eucharist is a true sacrifice, says the Church’s Catechism, “because it re-presents (makes present) the sacrifice of the Cross, .. and because it applies its fruit” (1366; emphasis in the original). The Eucharist applies to each repentant worshiper the fruit of Christ’s victory on the cross. Again, and in even stronger language, the Catechism asserts, “The Eucharist is the efficacious sign and sublime cause of that communion in the divine life and that unity of the People of God by which the Church is kept in being” (1325; emphasis added). Think of that! Through the Eucharist God maintains the very being of the ark of salvation, the Catholic Church.

When we take our part in the Eucharistic action, we allow Jesus to exercise his high priesthood in our behalf by re-presenting his perfect offering of himself to the Father for our salvation. We allow the Holy Spirit to apply to us the salvation won for us on the cross by God the Son. When we share in the Eucharist, we cooperate in the continuing process of our sanctification (“work out your own salvation. . .”). That process is never complete in this life. It must continue until we draw our last breath.

Now back to the original question. Why is it mortal sin, objectively speaking, to choose to stay away from Mass on Sundays or holy days of obligation? The answer is, by that decision, on that occasion, we turn our backs on Christ and on the process of our redemption. We refuse to carry out Christ’s command to “do this” for the recalling and receiving of him and his salvation.

The utter folly of what we do by willfully ignoring our Mass obligation is somewhat analogous to a deep-sea diver’s putting a crimp in his air line so that no air can come through to keep him alive. By a decision to miss Sunday Mass or a holy day of obligation we suspend the operation of sanctifying grace in our lives. For the sake of our eternal salvation, we must go to confession in true contrition as soon as possible and take the crimp out of our air line, so to speak, allowing sanctifying grace again to flood our souls.

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