Since the very beginning of the Church, the Mass has had a similar structure that has persisted throughout the centuries. While the manner in which the Mass has been celebrated has changed, the basic elements have not.
Liturgy of the Word
The first part of the Mass is generally labeled the Liturgy of the Word.
It is focused on listening to the Word of God and allowing it to enter into one's heart.
Within the Liturgy of the Word can be seen four key elements that the Catechism of the Catholic Church mentions.
1The Gathering
All gather together. Christians come together in one place for the Eucharistic assembly. At its head is Christ himself, the principal agent of the Eucharist. He is high priest of the New Covenant; it is he himself who presides invisibly over every Eucharistic celebration. It is in representing him that the bishop or priest acting in the person of Christ the head (in persona Christi capitis) presides over the assembly, speaks after the readings, receives the offerings, and says the Eucharistic Prayer. All have their own active parts to play in the celebration, each in his own way: readers, those who bring up the offerings, those who give communion, and the whole people whose "Amen" manifests their participation.
2Readings
The Liturgy of the Word includes "the writings of the prophets," that is, the Old Testament, and "the memoirs of the apostles" (their letters and the Gospels).
3Homily
After the homily, which is an exhortation to accept this Word as what it truly is, the Word of God, and to put it into practice...
4Intercessions
...come the intercessions for all men, according to the Apostle's words: "I urge that supplications, prayers, intercessions, and thanksgivings be made for all men, for kings, and all who are in high positions."
