How do liturgists decide on what readings get to be proclaimed at mass?

In some non-Catholic Christian churches, it is not unusual to hear the preacher talk about the Scripture passage that he or she has chosen to proclaim and to preach on. In the Catholic Church, as well as in a number of Protestant denominations with a liturgical tradition, the selection of Scripture readings is not left to the whim of the individual pastor. Rather, we follow a cycle of Scripture readings that was determined by the bishops, most recently after the Second Vatican Council, and set forth in a Lectionary. This cycle of readings is wedded to our liturgical calendar of feasts and seasons through which we enter more deeply into the experience of the life, death and resurrection of Jesus.

The Lectionary provides us with a “semi-continuous” reading of the Gospels arranged in a three-year cycle in which the Sunday readings of each year are dominated by a specific Gospel text: year A (the Gospel of Matthew); year B (the Gospels of Mark and John); and year C (the Gospel of Luke). John’s Gospel is also featured during most of Eastertide. The Old Testament readings and the Psalm responses were chosen to relate to the Gospel text. The second reading is usually a semi-continuous reading of one of the Letters, which is why it often does not neatly connect to the Gospel text.

During the seasons of Advent, Christmas, Lent, and Easter, as well as on solemnities, all of the Scripture readings are chosen to emphasize a particular theme or message of the feast or season.

The weekday readings also follow a cycle although it is a two-year cycle following odd and even years: year I for odd years; year II for even years. These cycles create a pattern and a flow that invites us to enter more deeply into the Paschal Mystery of Christ as the years go by and we change and grow as a result of our life experiences. In other words, we keep coming back to the same Scripture readings every three years, however, we are in a different place and, in a sense, we are different people than we were the last time we heard a specific Scripture story proclaimed. This cycle also exposes us to a great deal of the Bible over a 3-year period and ensures that all Catholics are unified in the celebration of the Liturgy instead of each priest selecting the readings he wants to proclaim and preach from. In other words, the cycle of Scripture readings is one example of our catholicity.