Q. 1. What is the Third Commandment and what sin does it condemn?
A. 1. The Third Commandment is, “Remember to keep holy the Lord's day.“
Why did God command the Sabbath to be kept holy? Because He completed the work of creation in six days and rested on the seventh day. “For in six days the Lord made heaven and earth, the sea, and all that is in them, but rested the seventh day; therefore the Lord blessed the Sabbath day and consecrated it.” [Exo. 20:11]
Note: The Catholic Church teaches that six days does not necessarily mean six days of twenty-four hours each, but rather six periods of time of any length. Accordingly, a day could be symbolic of ten thousand years.
Why do we keep holy the first day of the week instead of the Sabbath, or seventh day? We do so on the authority of the Apostles. We know the Apostles selected Sunday instead of the Sabbath to hold their Christian meetings, because Christ rose from the dead on Sunday, and the Holy Ghost came down upon the Apostles on Sunday (Pentecost). “And on the first day of the week, when we met to break bread, Paul was holding a discussion with them...” [Act. 20:7]
The Sunday celebration of the Lord's Day and his Eucharist is at the heart of the Church's life. ‘Sunday is the day on which the paschal mystery is celebrated in light of the apostolic tradition and is to be observed as the foremost holy day of obligation in the universal Church.’ [CIC, can. 1246 § 1]” (C.C.C. # 2177) How are Catholics obliged to keep Sunday holy? They are obliged to attend Holy Mass on Sunday. They are to abstain from doing unnecessary work on Sunday. They are to avoid shopping on Sunday.
The precept of the Church specifies the law of the Lord more precisely: ‘On Sundays and other holy days of obligation the faithful are bound to participate in the Mass.’ [CIC, can. 1247] ‘The precept of participating in the Mass is satisfied by assistance at a Mass which is celebrated anywhere in a Catholic Rite either on the holy day or on the evening of the preceding day.’ [CIC, can. 1248 § 1] (C.C.C. # 2180) (Note: “precept” means “teaching.”)
A parish is a definite community of the Christian faithful established on a stable basis within a particular church; the pastoral care of the parish is entrusted to a pastor as its own shepherd under the authority of the diocesan bishop." [CIC, can. 515 § 1] It is the place where all the faithful can be gathered together for the Sunday celebration of the Eucharist. The parish initiates the Christian people into the ordinary expression of the liturgical life: it gathers them together in this celebration; it teaches Christ's saving doctrine; it practices the charity of the Lord in good works and brotherly love. (C.C.C. # 2179)
You cannot pray at home as at church, where there is a great multitude, where exclamations are cried out to God as from one great heart, and where there is something more: the union of minds, the accord of souls, the bond of charity, the prayers of the priests. (C.C.C. # 2179)
What would excuse a person from his obligation of attending Mass? Illness, or the duty of attending the sick. A necessary obligation during the hours of the Holy Mass. (Example: The house is on fire or a water line just broke in the house.) Living at a great distance from a Church where a priest will be celebrating the Holy Mass. (Note: If a person must walk versus driving, a "great distance" is judged differently. For example, it would not be unreasonable to have to walk 2 miles to Church, or to drive 30 miles to Church. It may be difficult to have to walk 10 miles to Church or drive 100 miles every Sunday.
Those who deliberately fail in this obligation commit a grave sin. (C.C.C. # 2181) When you commit a grave sin, you cannot receive the Sacrament of the Holy Eucharist until such time as you have confessed your grave sin. What kind of labour is permitted on Sunday? Any of the following trades that are required to work on Sunday: doctors, nurses, pharmacists, policemen, firemen, 911 telephone operator, prison guards, utility maintenance during major storms, etc... providing their working days cannot be rotated with another employee.
Besides attending Mass and abstaining from work, how are we asked to spend Sunday? We are asked to spend it in a manner becoming the Lord’s Day; attending an afternoon or evening service in the Church, and devoting some time to devout reading and prayer. Are we forbidden from participating in any form of amusements on Sunday? No. Such amusements and relaxations as they are innocent in themselves may be indulged in, so long as they do not interfere with our religious obligations.
Note: When a person drives 100 miles to go to his Summer cottage for the weekend but he will not drive 5 miles to the nearest Church on Sunday morning to attend Holy Mass, this person is breaking the Third Commandment. The Third Commandment is also broken when a mother is willing to drive her son the distance of 20 miles three times a week for his hockey practices, but she will not drive 10 miles to go to Church on Sunday. It becomes obvious that hockey practices are more important than honouring the Lord's Day.
If because of lack of a sacred minister or for other grave cause participation in the celebration of the Eucharist is impossible, it is specially recommended that the faithful take part in the Liturgy of the Word if it is celebrated in the parish church or in another sacred place according to the prescriptions of the diocesan bishop, or engage in prayer for an appropriate amount of time personally or in a family or, as occasion offers, in groups of families.[CIC, can. 1248 § 2] (C.C.C. # 2183)
Note: When there is another Church within a reasonable distance, in the absence of a priest at their Church, the faithful are obligated to attend Holy Mass at the other Church. The Liturgy of the Word by a lay person does not substitute attendance at the Holy Mass. In fact, the person who does not attend Holy Mass when another Church is within a reasonable distance, that person commits a grave sin which must be confessed because he can once more receive the Sacrament of the Holy Eucharist.