Theology

The Eucharist - Source and Summit of Ecclesial Life: The Eucharist is the "source and summit of the Christian life" The other sacraments, and indeed all ecclesial ministries and works of the apostolate, are bound up with the Eucharist and oriented toward it. For in the blessed Eucharist is contained the whole spiritual good of the Church, namely Christ Himself, our Pasch. (CCC 1324)

The Presence of Christ: Four-fold Presence: Christ is always present in his Church, especially in its liturgical celebrations. He is present in the sacrifice of the Mass, not only in the person of his minister, "the same now offering, through the ministry of priests, who formerly offered himself on the cross," but especially in the Eucharistic elements. By his power he is present in the sacraments, so that when a man baptizes it is really Christ himself who baptizes. He is present in his word, since it is he himself who speaks when the Holy Scriptures are read in the Church. He is present lastly when the Church prays and sings, for he promised "Where two or three are gathered together in my name, there am I in the midst of them" (Mt 18:20 ). (Sacrosanctum Concilium 7)

• In the celebration of the Liturgy, the word of God is not announced in only one way, nor does it always stir the hearts of the hearers with the same efficacy. Always, however, Christ is present in his word, as he carries out the mystery of salvation, sanctifies humanity, and offers the Father perfect worship. (SC7)
• Moreover, the word of God unceasingly calls to mind and extends the economy of salvation, which achieves its fullest expression in the Liturgy. The liturgical celebration becomes therefore the continuing, complete and effective presentation of God's word. The word of God constantly proclaimed in the Liturgy is always, then, a living and effective word through the power of the Holy Spirit. It expresses the Father's love that never fails in its effectiveness toward us. (Introduction to Lectionary for Mass 4)
• Whenever the Church, gathered by the Holy Spirit for liturgical celebration, announces and proclaims the word of God, she is aware of being a new people in whom the covenant made in the past is perfected and fulfilled. Baptism and confirmation in the Spirit have made all Christs faithful into messengers if God's word because of the grace of hearing they have received. They must therefore be the bearers of the same word in the Church and in the world, at least by the witness of their lives. (ILM 7)

Participation In the Liturgy: Full: conscious and active participation: The church earnestly desires that all the faithful be led to that full, conscious, and active participation in liturgical celebrations called for by the very nature of the liturgy. Such participation by the Christian people as a "chosen race, a royal priesthood, a holy nation, God's own people" (1 Pet 2:9) is their right and duty by reason of their baptism. (SC 14)
This "full, active and conscious participation" demands several things of the Faithful, especially those desiring to serve the Church as lectors. First, it demands the practice of one's faith publicly. This would include regular Mass attendance, regularity of one's marriage in the Church, avoidance of public scandal, and observance of the precepts of the church. Second, it demands an interior participation in the Liturgy. This involves developing a relationship with the Lord, through prayer, through acts that foster humility, and by being willing to "wash the feet of others".
Third, it demands listening to the word of God and keeping it. Christ is present in the words of Scripture. It is important to listen attentively to the Word of God at Mass. The word of God leads the Faithful to the Sacrament. In the word of God, the divine covenant is announced; in the Eucharist, the new and everlasting covenant is renewed. On the one hand, the history of salvation is brought to mind by human sounds; on the other it is made manifest in the sacramental signs of the Liturgy. It can never be forgotten, therefore, that the divine word read and proclaimed by the church in the Liturgy has as its purpose the sacrifice of the New Covenant and the banquet of grace, that is the Eucharist. (ILM 10) It is important to spend time with the scriptures outside of public worship.
Fourth, active participation in the liturgy has an exterior manifestation of the liturgy through singing. We sing the liturgy if thanksgiving and praise to God. Fifth, one can actively participate in the liturgy by serving the Church through ministry. There are many other ways in which the people of God can actively participate in the liturgy.

The Collaboration of the Non-ordained Faithful in the Pastoral Ministry: Indeed, "when necessity and expediency in the Church require it, the pastors according to established norms from universal law , can entrust to the lay faithful certain offices and roles that are connected to their pastoral ministry but do not require the character of orders." (Christifideles Laici 23) In this way, it is not merely one of assistance but of mutual enrichment of the common Christian vocation.
Liturgical tradition assigns responsibility for biblical readings in the celebration of Mass to ministers, to readers and the deacon. But when there is no deacon or other priest present, the priest celebrant is to read the Gospel. (GIRM 34) The liturgical assembly truly requires readers, even those not instituted. Proper measures must therefore be taken to ensure that there are certain suitable laypeople who have been trained to carry out this ministry. (Inaestimabile Donum 2)