The Eucharist
The Council of Trent
Session XIII: Decree Concerning the Most Holy Sacrament of the Eucharist.
Chapter I: On the Real Presence of our Lord Jesus Christ in the Most Holy Sacrament of the Eucharist.
In the first place, the holy Synod teaches, and openly and simply professes, that, in the august sacrament of the holy Eucharist, after the consecration of the bread and wine, our Lord Jesus Christ, true God and man, is truly, really, and substantially contained under the species of those sensible things.
Chapter III: On the Excellency of the Most Holy Eucharist over the Rest of the Sacraments.
And this faith has ever been in the Church of God, that, immediately after the consecration, the veritable body of our Lord, and his veritable blood, together with his soul and divinity, are under the species of bread and wine…Wherefore it is most true, that as much is contained under either species as under both; for Christ whole and entire is under the species of bread, and under any part whatsoever of that species; likewise the whole (Christ) is under the species of wine, and under the parts thereof.
Chapter IV: On Transubstantiation.
And because that Christ, our Redeemer, declared that which he offered under the species of bread to be truly his own body, therefore has it ever been a firm belief in the Church of God, and this holy Synod doth now declare it anew, that, by the consecration of the bread and of the wine, a conversion is made of the whole substance of the bread into the substance of the body of Christ our Lord, and of the whole substance of the wine into the substance of his blood; which conversion is, by the holy Catholic Church, suitably and properly called Transubstantiation.
Chapter V: On the Cult and Veneration to be Shown to This Most Holy sacrament.
Wherefore, there is no room left for doubt, that all the faithful of Christ may, according to the custom ever received in the Catholic Church, render in veneration the worship of latria, which is due to the true God, to this most holy sacrament. For not therefore is it the less to be adored on this account, that it was instituted by Christ, the Lord, in order to be received; for we believe the same God to be present therein, of whom the eternal Father, when introducing him into the world, says: And let all the angels of God worship him, whom the Magi, falling down, adored; who, in fine, as the Scripture testifies, was adored by the apostles in Galilee.
Canon I. If any one denieth, that, in the sacrament of the most holy Eucharist, are contained truly, really, and substantially, the body and blood together with the soul and divinity of our Lord Jesus Christ, and consequently the whole Christ; but saith that he is only therein as in a sign, or in a figure, or virtue; let him be anathema.
Canon II. If any one saith, that, in the sacred and holy sacrament of the Eucharist, the substance of the bread and wine remains conjointly with the body and blood of our Lord Jesus Christ, and denieth that wonderful and singular conversion of the whole substance of the bread into the body, and of the whole substance of the wine into the blood—the species only of the bread and wine remaining—which conversion indeed the Catholic Church most aptly calls Transubstantiation: let him be anathema.
Canon VI. If any one saith, that, in the holy sacrament of the Eucharist, Christ, the only-begotten Son of God, is not to be adored with the worship, even external of latria; and is, consequently, neither to be venerated with a special festive solemnity, nor to be solemnly borne about in procession, according to the laudable and universal rite and custom of holy Church; or, is not to be proposed publicly to the people to be adored, and that the adorers thereof are idolators: let him be anathema.
Canon VIII. If any one saith, that Christ, given in the Eucharist, is eaten spiritually only, and not also sacramentally and really: let him be anathema (The Canons and Decrees of the Council of Trent, in Philip Schaff, The Creeds of Christendom(Grand Rapids: Baker, 1919 ed.), pp. 126-131, 136-138).
Vatican II
Christ is always present in His Church, especially in her 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 under the Eucharistic species.
At the Last Supper, on the night when He was betrayed, our Savior instituted the Eucharistic Sacrifice of His Body and Blood. He did this in order to perpetuate the sacrifice of the Cross throughout the centuries until He should come again.
In the house of prayer the most Holy Eucharist is celebrated and preserved. There the faithful gather, and find help and comfort through venerating the presence of the Son of God our Savior, offered for us on the sacrificial altar (The Documents of Vatican II, Walter M. Abbott, S.J., General Editor. (Chicago: Follett, 1966), pp. 140-141, 154, 543).
The Code of Canon Law
Canon 897: The most venerable sacrament is the blessed Eucharist, in which Christ the Lord himself is contained, offered and received, and by which the Church continually lives and grows. The eucharistic Sacrifice, the memorial of the death and resurrection of the Lord, in which the Sacrifice of the cross is forever perpetuated, is the summit and the source of all worship and christian life.
Canon 898: Christ’s faithful are to hold the blessed Eucharist in the highest honour. They should take an active part in the celebration of the most august Sacrifice of the Mass; they should receive the sacrament with great devotion and frequently, and should reverence it with the greatest adoration.
Canon 899: The celebration of the Eucharist is an action of Christ himself and of the Church. In it Christ the Lord, through the ministry of the priest, offers himself, substantially present under the appearances of bread and wine, to God the Father, and gives himself as spiritual nourishment to the faithful who are associated with him in his offering.
Canon 904: Remembering always that in the mystery of the eucharistic Sacrifice the work of redemption is continually being carried out, priests are to celebrate frequently (The Code of Canon Law (London: Collins, 1983).
The Question and Answer Catholic Catechism
1217. Is the Eucharist necessary for salvation?
The Eucharist is necessary for salvation, to be received either sacramentally or in desire. Christ’s words, “if you do not eat the flesh of the Son of Man and drink his blood, you will not have life in you” (John 6:53), mean that Holy Communion is necessary to sustain the life of grace in a person who has reached the age of reason(John Hardon, The Question and Answer Catholic Catechism(Garden City: Image, 1981).