Eucharist
The liturgical life of the Church revolves around the sacraments, with the Eucharist at the center (National Directory for Catechesis, #35). At Mass, we are fed by the Word and nourished by the Body and Blood of Christ. We believe that the Risen Jesus is truly and substantially present in the Eucharist. The Eucharist is not a sign or symbol of Jesus; rather we receive Jesus Himself in and through the Eucharistic species (the appearances of bread and wine). The priest, through the power of his ordination and the action of the Holy Spirit, changes the core "substance" of the bread and wine into the whole Body and Blood of Jesus, hidden in what appears to be bread and what tastes like wine. This change is called "transubstantiation," the change of the substance into the whole Christ, while leaving only the quantitative qualities ("species") of bread and wine--without their substance. As the Catechism of the Catholic Church (CCC) explains,
By the consecration, the transubstantiation of the bread and wine into the Body and Blood of Christ is brought about. Under the consecrated species of bread and wine, Christ Himself, living and glorious, is present in a true, real, and substantial manner: His Body and his Blood, with His soul and His divinity. (CCC 1413)
The mode of Christ's presence under the Eucharistic species is unique. ... In the most Blessed Sacrament of the Eucharist "the Body and Blood, together with the soul and divinity, of our Lord Jesus Christ and, therefore, the whole Christ is truly, really, and substantially contained." "This presence is called 'real' - by which is not intended to exclude the other types of presence as if they could not be 'real' too, but because it is presence in the fullest sense: That is to say, it is a substantial presence by which Christ, God and man, makes Himself wholly and entirely present."
(CCC 1374)
By "entirely" present, it is meant that every quality and aspect of Jesus Christ--His hair, His eyes, His emotions--are fully and totally present, though hidden under sacramental forms, whenever we visit Him reposed in the tabernacle or exposed in a monstrance during Adoration and Benediction.
This also means that whenever we receive Holy Communion, we should not refer to the consecrated Host as "bread" (because it is actually not bread) but truly as the Body of the living, resurrected Christ; similarly, we should not refer to "wine" (because it is actually not wine) but to the Precious Blood of our Savior.
The New Covenant
I am the living Bread that came down from heaven; whoever eats this Bread will live forever;…Whoever eats My Flesh and drinks My Blood has eternal life and…remains in Me and I in Him. (John 6:51, 54, 56)
In the gospels we read that the Eucharist was instituted at the Last Supper. This is the fulfillment of the covenants in the Hebrew Scriptures. In the Last Supper narratives, Jesus took, broke and gave bread and wine to his disciples. In the blessing of the cup of wine, Jesus calls it “the Blood of the covenant” (Matthew and Mark) and the “new covenant in My Blood” (Luke).
This reminds us of the blood ritual with which the covenant was ratified at Sinai (Ex 24) -- the sprinkled blood of sacrificed animals united God and Israel in one relationship, so now the shed Blood of Jesus on the cross is the bond of union between new covenant partners -- God the Father, Jesus, and the Catholic Christian Church. Through Jesus’ sacrifice, all the baptized are in relationship with God, although the fullness of the truth subsists in the Catholic Church, the Church instituted by Christ and entrusted to His apostles (with Peter as their head) and their successors, i.e., the bishops who are in communion with the successor of St. Peter (the Pope), the Bishop of Rome (see CCC 816, 820, 830). This "handing on" of the faith (what "Tradition" means) from generation to generation through the teaching of the apostle's successors (bishops) assures us that the Church, divinely guided by the Holy Spirit, receives and develops faithfully the teachings of the Lord Jesus to His apostles; in other words, it is essential that the Church be "apostolic," i.e., connected by succession to the apostles, the 12 disciples to whom Jesus entrusted His Church, because apostolic succession is a guarantee of being connected with the original Church that Jesus promised His eternal guidance and protection (Matthew 16:18).
The Catechism teaches that all Catholics who have received their First Holy Communion are welcome to receive Eucharist at Mass unless in a state of mortal sin.
Anyone who desires to receive Christ in Eucharistic communion must be in the state of grace. Anyone aware of having sinned mortally must not receive communion without having received absolution in the sacrament of Penance. (CCC 1415)
The Church warmly recommends that the faithful receive Holy Communion when they participate in the celebration of the Eucharist; she obliges them to do so at least once a year. (CCC 1417)
Receiving the Eucharist changes us. St. Augustine would say, "Be what you see; receive what you are"--the Body of Christ. It signifies and effects the unity of the community, the mystical (spiritual and invisible) Body of Christ and serves to strengthen each member.
Understanding the Mass
The central act of worship in the Catholic Church is the Mass. It is in the liturgy that the saving death and resurrection of Jesus once for all is made present again in all its fullness and promise – and we are privileged to share in His Body and Blood, fulfilling his command as we proclaim his death and resurrection until He comes again. It is in the liturgy that our communal prayers unite us into the Body of Christ. It is in the liturgy that we most fully live out our Christian faith.
The liturgical celebration is divided into two parts: the Liturgy of the Word and the Liturgy of the Eucharist. First we hear the Word of God proclaimed in the scriptures and respond by singing God’s own Word in the Psalm. Next that Word is broken open in the homily. We respond by professing our faith publicly. Our communal prayers are offered for all the living and the dead in the Creed. Along with the Presider, we offer in our own way, the gifts of bread and wine and are given a share in the Body and Blood of the Lord, broken and poured out for us. We receive the Eucharist, Christ’s real and true presence, and we renew our commitment to Jesus. Finally, we are sent forth to proclaim the Good News!
The other sacraments, and indeed all ecclesiastical ministries and works of the apostolate, are bound up with the Eucharist and are oriented toward it. (CCC 1324)
