The Catholic Mass

What the Church believes about the Mass, how the readings are arranged, and how to take part well.

The Catholic understanding

The Mass is the memorial of Christ’s Passover. In it His one sacrifice on the Cross is made present and offered, and its fruit is applied to us (CCC 1362, 1366). “The sacrifice of Christ and the sacrifice of the Eucharist are one single sacrifice”; only the manner of offering is different (CCC 1367).

In the Eucharist, Christ Himself is present, Body and Blood, soul and divinity: “the whole Christ is truly, really, and substantially contained” (CCC 1374). This is why the Church calls the Eucharist “the source and summit of the Christian life” (CCC 1324; Lumen Gentium 11).

The Mass has two main parts, the Liturgy of the Word and the Liturgy of the Eucharist. They are so closely joined that they “form but one single act of worship” (Sacrosanctum Concilium 56; CCC 1346).

“He is present in His word, since it is He Himself who speaks when the holy scriptures are read in the Church” (Sacrosanctum Concilium 7; CCC 1088).

On Sundays and other Holy Days of Obligation the faithful are bound to take part in the Mass, either on the day itself or on the evening before (CCC 2180). The Sunday Eucharist is “the foundation and confirmation of all Christian practice.” A serious reason, such as illness or the care of infants, excuses us; to miss deliberately is a grave sin (CCC 2181). Studies for the Holy Days, such as the Immaculate Conception on December 8, are listed in the Contents.

The readings and the cycles

“In the readings, the table of God’s Word is spread before the faithful, and the treasures of the Bible are opened to them” (GIRM 57). Sundays and solemnities have three readings, from a prophet, an apostle and a Gospel, so that we see “the continuity of the work of salvation” (GIRM 357). The First Reading is usually from the Old Testament; in Easter Time it comes from the Acts of the Apostles (GIRM 357).

• The First Reading. On Sundays the Old Testament reading is chosen mainly for its connection with the Gospel (Lectionary Introduction 67). This brings out the unity of the two Testaments, and over the years nearly all the principal pages of the Old Testament become familiar to those at Sunday Mass (Lectionary Introduction 106).
• The Responsorial Psalm. It is “an integral part of the Liturgy of the Word,” chosen to correspond to the reading, and it “fosters meditation on the Word of God” (GIRM 61).
• The Second Reading. On the Sundays of Ordinary Time it is a semicontinuous reading of the letters of Saint Paul and Saint James, so that week by week we move through one letter (Lectionary Introduction 67, 107).
• The Gospel. It is “the high point of the Liturgy of the Word,” set apart by special marks of honor, and we stand to hear it (GIRM 60). The Alleluia, sung by all standing, greets “the Lord who is about to speak to them in the Gospel.” In Lent another acclamation takes its place (GIRM 62).
• The Homily. It explains some aspect of the readings, and it is necessary “for the nurturing of the Christian life” (GIRM 65).

The Sunday readings follow a three-year cycle (Lectionary Introduction 66). Each year is named for the Gospel read through Ordinary Time: Year A for Matthew, Year B for Mark and Year C for Luke. In Year B, five Sundays in summer turn to Jesus’ discourse on the Bread of Life in John 6 (Lectionary Introduction 105). The Gospel of John is read in the latter weeks of Lent and in Easter Time (Lectionary Introduction 74). Each year of the cycle begins on the First Sunday of Advent (Lectionary Introduction 66), and the site’s Contents page shows which year each study follows.

Weekdays have their own plan, with two readings. In Ordinary Time the weekday Gospels follow a single cycle repeated each year, while the First Reading follows a two-year cycle: Year I in odd-numbered years and Year II in even-numbered years. In Advent, Christmas Time, Lent and Easter Time the weekday readings are the same every year (Lectionary Introduction 69).

The seasons shape the readings as well. Advent reads above all from Isaiah. Christmas Time adds the First Letter of John. Easter Time reads the Acts of the Apostles (Lectionary Introduction 74). In Lent the Old Testament readings trace the history of salvation (Lectionary Introduction 97). Through Ordinary Time the Gospel is read in order, as the Lord’s life and preaching unfold (Lectionary Introduction 105).

This plan answers the Council’s wish: “The treasures of the bible are to be opened up more lavishly, so that richer fare may be provided for the faithful at the table of God’s word” (Sacrosanctum Concilium 51). The studies on this site follow the same Sunday cycle, one week at a time.

Best practices

1. Prepare with the readings. Read the Sunday readings a day or two ahead and pray with them. Each study here links to them on the USCCB.
2. Keep the Eucharistic fast. Abstain from food and drink, except water and medicine, for at least one hour before Holy Communion. The elderly, the sick and those who care for them are excused (Code of Canon Law 919).
3. Arrive early and keep silence. Silence in the church before Mass helps everyone prepare to celebrate devoutly (GIRM 45).
4. Genuflect to the Lord. A genuflection, bending the right knee to the ground, is a sign of adoration reserved for the Blessed Sacrament (GIRM 274). Make it toward the tabernacle as you enter your pew.
5. Take part. Join in the responses, the prayers and the singing. The Church desires “fully conscious, and active participation” from all the faithful; it is their “right and duty by reason of their baptism” (Sacrosanctum Concilium 14).
6. Listen to Christ speaking. When the readings begin, listen as to the Lord Himself. In the readings “God speaks to his people,” and Christ is present through His word (GIRM 55).
7. Receive Communion worthily. Anyone conscious of grave sin must go to Confession before receiving Communion (CCC 1385; Code of Canon Law 916). In the United States, Communion is normally received standing, with a bow of the head first; you may kneel if you wish, and you may receive the host on the tongue or in the hand (GIRM 160-161).
8. Give thanks. After Communion, praise God in your heart and pray to Him in silence (GIRM 45). After the final blessing, stay a moment if you can.
9. Carry one line into the week. Take one phrase from the readings home with you and return to it each day.