As we mentioned in an earlier post, the Bishops of Scotland announced that the obligation to attend Mass on Sundays and Holy Days of Obligation is to be restored from this Sunday 6th March (1st Sunday of Lent).
To understand the reasons for the obligation to participate in mass on Sundays and Holy Days of Obligation, a really good resource is the Apostolic Letter Dies Domini by St. John Paull II.
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.
Catechism of the Catholic Church, paragraph 2181