The Constitution of the Sacred Liturgy (one of Vatican II's documents) states: "Within the cycle of a year. . . The church unfolds the whole mystery of Christ . . . from his incarnation and birth until his ascension. . . " The Catechism of the Catholic Church tells us: "We must continue to accomplish in ourselves the stages of Jesus' life and his mysteries. . . For it is the plan of the Son of God to make us and the whole church partake in his mysteries and to extend them and to continue them in us and in his whole church" (#1095). So through the ebb and flow of each liturgical year we seek, with the guidance of our church, to live and internalize the events of Christ's life.
Two Main Seasons and Two In-Between Times
Nature has four seasons: spring, summer, autumn and winter. Our church year has two main seasons. In between these two seasons we have two sets of Ordinary Time.
The two main seasons are the Advent-Christmas season and the Lent-Easter season. Christmas celebrates the Incarnation of Jesus, God becoming one of us. Easter celebrates the death and resurrection of Christ. Each season has a time of preparation. We prepare for the Feast of the Incarnation with four weeks of Advent. We prepare for the (Holy Thursday, Good Friday and Easter Vigil) with 40 days of Lent. Both events (the Incarnation and our Redemption) have an extended period of celebration. We don't just celebrate Christ's coming on Christmas Eve and Christmas Day. We celebrate it for twelve days culminating in the Baptism of Jesus. We do not just celebrate Christ's resurrection on Easter Sunday. We celebrate it for 50 days of Easter culminating with the Feast of Pentecost.
So, in our church year calendar, the two great seasons of the year are the Advent-Christmas season and the Lent-Easter season. The latter being the more important of the two because it celebrates Christ's death and resurrection. One-third of Mark's Gospel is given to the Passion, Death and Resurrection of Jesus.
Ordinary Time
For the next several Sundays, you may hear us say, "Today is the second, third, fourth Sunday in Ordinary Time." Ordinary is not intended to suggest unimportant time. Rather, Ordinary means "not seasonal" or not extraordinary time. Ordinary Time covers the weeks and Sundays not included in the two big seasons of the year. In our church's year, we have two sets of Ordinary Time Sundays. The first set begins at the end of the Christmas season (which was last Sunday) and continues until the Sunday before Ash Wednesday. The second set of Ordinary Sundays begins at the end of the Easter season which is Pentecost Sunday and continues through all summer and fall till the end of November when another new church year begins. There are 34 weeks in Ordinary Time. This Sunday, in our church calendar, is called the Second Sunday in Ordinary Time. You may ask what happened to the first Sunday? We don't have one. Ordinary Time started last Monday. The first week of Ordinary Time doesn't have a first Sunday. It would have been last Sunday, which was the Baptism of the Lord.
Other Solemnities and Feasts in Our Church Year
In addition to the two major seasons and the 34 Sundays of Ordinary Time, the church has several special solemn feasts. For example: Trinity Sunday, Corpus Christi (Body of Christ), Christ the King, Immaculate Conception of Mary, Assumption of Mary.
In addition, our liturgical calendar is filled with the feasts of saints, some of whom were killed as they witnessed to Christ. These we call martyrs. The saints are people who cooperated with God's grace in an extraordinary way. We celebrate their feast on the day they died, which is the day they entered heaven. Saints are the heroes and heroines of our church family, our role models of how to follow Christ.
Three Cycles--A, B, C
Our Sunday Lectionary (lectio--to read) and Book of the Gospels contains three set cycles of readings, A, B & C, which correspond to the first three gospels: Matthew (read in cycle A), Mark (cycle B) and Luke (cycle C). We do not read the total gospel in a particular year, but the vast majority of it is proclaimed.
We hear excerpts from the gospel of John during all three cycles of the Easter season (seven Sundays and during several Sundays of the B cycle when we listen to Mark--the shortest of the gospel). We will also hear some stories from John during Lent, especially in cycles A and B. Most mainline Protestant churches follow a three year cycle. Without such a mandated set of readings, preachers would only have to preach on passages that appealed to them.
The first reading
The compilers of the lectionary choose the first reading to harmonize with the main focus of the gospel. Often the connection is quite obvious, sometimes it is not at all obvious. During the Easter season the first reading is not from the Old Testament, it is from The Acts of the Apostles, which among other things narrates the beginnings of the Christian church after the resurrection of Christ.