And who told you THAT ? Did you ask them for their source?
re; Mass, From the CCC (all emphasis mine)
**2042 **The first precept (“You shall attend Mass on Sundays and holy days of obligation and rest from servile labor”) requires the faithful to sanctify the day commemorating the Resurrection of the Lord as well as the principal liturgical feasts honoring the Mysteries of the Lord, the Blessed Virgin Mary, and the saints; in the first place, by participating in the Eucharistic celebration, in which the Christian community is gathered, and by resting from those works and activities which could impede such a sanctification of these days.
The second precept (“You shall confess your sins at least once a year”) ensures preparation for the Eucharist by the reception of the sacrament of reconciliation, which continues Baptism’s work of conversion and forgiveness. The third precept (“You shall receive the sacrament of the Eucharist at least during the Easter season”) guarantees as a minimum the reception of the Lord’s Body and Blood in connection with the Paschal feasts, the origin and center of the Christian liturgy.
**2178 **This practice of the Christian assembly dates from the beginnings of the apostolic age. The
Letter to the Hebrews reminds the faithful “not to neglect to meet together, as is the habit of some, but to encourage one another.” #
22 shows the consequences if one deliberately misses mass on Sunday or any holy day of obligation]
Tradition preserves the memory of an ever-timely exhortation: Come to Church early, approach the Lord, and confess your sins, repent in prayer. . . . Be present at the sacred and divine liturgy, conclude its prayer and do not leave before the dismissal. . . . We have often said: “This day is given to you for prayer and rest. This is the day that the Lord has made, let us rejoice and be glad in it.”
2180 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.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.”
2181 The Sunday Eucharist is the foundation and confirmation of all Christian practice. For this reason the faithful are obliged to participate in the Eucharist on days of obligation, unless excused for a serious reason (for example, illness, the care of infants) or dispensed by their own pastor. Those who deliberately fail in this obligation commit a grave sin.
(grave, as in mortal sin)
2182 Participation in the communal celebration of the Sunday Eucharist is a testimony of belonging and of being faithful to Christ and to his Church. The faithful give witness by this to their communion in faith and charity. Together they testify to God’s holiness and their hope of salvation. They strengthen one another under the guidance of the Holy Spirit.
2183 “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.”
“encourage” is
NOT the whole answer. There’s an or else, a mortal consequence for one’s soul, that goes along with one deliberately missing mass on Sunday.
You’re a catechist. Teach what has been written for all to see and know, in the scriptures and Church teaching. Don’t treat this lightly. For your own soul and the ones you teach.