This commandment contains two main ideas and one key concept that sheds light on the rest of our lives. First, it’s about rest and the value it has for everyone who works and has to earn a living. And second, “keeping the Lord’s day holy” means giving God the kind of worship He wants from us: the Holy Mass. And the key concept that can illuminate our whole lives is the value of the Mass itself and the real presence of Jesus Christ in the Eucharist, a gift of love that the Lord has given us.

God commands us to take care of ourselves. This is a helpful way to understand part of the third commandment. Hard work, worries, and the weight of our responsibilities can make us lose perspective and forget to notice the beauty God places before us. Resting in God means making space — inside and outside — to step back from our everyday concerns, to view things from above, and to think about them with the wise outlook of a provident Father.

This is what making the Lord’s Day holy, or “sanctifying” Sundays, really means. Simple things make it a holy day: spending time with family, or going to do works of mercy (visiting the sick, the elderly, or people who are alone) with our families. Sunday helps us to be more aware of God’s presence, and to thank Him particularly for the gift of rest.

Saint John Paul II once said: “Today I would like to urge everyone to rediscover Sunday: do not be afraid to give your time to Christ! Yes, let us open our time to Christ so that He may enlighten it and guide it. He knows the secret of time and the secret of eternity, and He gives us ‘his day’ as a constantly renewed gift of his love. Discovering this day is a grace we must ask for, not only to live the demands of faith to the full, but also to give a concrete answer to the deep and authentic longings of every human being. The time offered to Christ is never time lost, but rather time gained for the deep humanisation of our relationships and our life” (Apostolic Letter Dies Domini, nos. 4 and 7).

One of the saints, writing to the early Christians, said: “The Lord’s day, the day of the Resurrection, the day of Christians, is our day. That is why it is called the Lord’s day: because on this day the Lord ascended victorious to the Father. If pagans call it the day of the sun, we accept the name gladly, for today has risen the light of the world; today the sun of justice has appeared, whose rays bring salvation” (Saint Jerome, In die Dominica Paschae homilia, cf. Catechism of the Catholic Church, no. 1166).

Worshipping God shouldn’t be understood in a negative sense, as if God “needed” our praise. It’s our need; the need to remember and celebrate the wonders God has done, to give Him thanks and praise. Mass is taking part in the celebration of the mystery of Jesus Christ, who redeemed us.

At every Mass, no matter who is celebrating or attending it, we relive the mysteries that gave us new life: Jesus’s death and resurrection. At each Mass we ask forgiveness with Christ for our sins, we offer God the worship most pleasing to Him (the death and resurrection of His Son), we present our needs with Christ who intercedes for us, and we give thanks by offering what is the fruit of human work and becomes the most perfect offering: the very Son of God, Jesus Christ.

The Mass also has a cosmic dimension: the whole Church is there in every Mass, even if no one else is physically present, together with all of creation. As you can see, the Mass is far more than a nice time to pray with the community.

The part of this commandment that can shine a light on our whole lives is the Real Presence of Jesus. Why are we asked to take part in the Mass? The straightforward answer is, “because God is there.” Because Jesus becomes present on the altar, so we can receive Him, praise Him, or simply allow ourselves to be filled by his Presence and his Word.

It might help to remember that if we prepare ourselves to welcome the Lord into our soul and our heart now, He will welcome us into his home, too, when we leave this world.