The Scriptures read at Sunday Mass are not arbitraily chosen by the pastor or parishioner. The Church has a three-year cycle of set readings.
In this cycle, Year One centers on Matthew's Gospel, Year Two on Mark, and Year Three on Luke. (Passages from Hohn are interspersed in the sequence of Gospels every year.)
The Weekday Gospels
The weekday Gospels, however, are the same every year. Since there are many more weekdays than Sundays, they cover a greater part of all four Gospels.
Generally speaking, the weekday Gospels use passages that are never read on Sundays
During Advent we will use the Gospel passaged assigned for the weekday Masses. This will give many a chance to reflect on and pray passages of the Gospels that they have seldom heard proclaimed or preached at Liturgy.
