The historical roots of Roman Catholic Eucharistic theology are the basis upon which a number of ecclesial communities, or churches, express their faith in the "bread of life" as given by Jesus, and are to be found in the Church Fathers, Scripture, the writings of Thomas Aquinas, and other early church writings and traditions.
The three synoptic Gospels and Paul's First Letter to the Corinthians contain versions of the Words of Institution: "Take, eat, this is my body.... Take, drink, this is my blood.... Do this in remembrance of me." All subsequent celebration of the Eucharist is based on this injunction. The primary theological paradigm is rooted in New Testament passage John 6:47-67, key to grasping how the disciples of Jesus and the first Christians understood the Eucharist. In a central portion of this passage (6:51-54), Jesus states:
From the earliest Christian documents, such as the Didache, the understanding follows this pattern: that the bread and wine that is blessed and consumed at the end of the (transformed) Passover meal literally is the body and blood of Jesus, and was treated accordingly: "Let no one eat or drink of the Eucharist with you except those who have been baptized in the name of the Lord; for it was in reference to this that the Lord said: 'Do not give that which is holy to dogs'" (Jurgens §6). The Didache also enjoins "confessing your transgressions so that your sacrifice may be pure" (Jurgens §8). Others state explicitly that the consecrated bread and wine is indeed the body and blood of Christ. St. Ignatius of Antioch, who was martyred in ca. 107, wrote: "I have no taste for corruptible food nor for the pleasures of this life. I desire the Bread of God, which is the Flesh of Jesus Christ, who was of the seed of David; and for drink I desire His Blood, which is love incorruptible" (Jurgens §54a). He recommended Christians to stay aloof from heretics who "confess not the Eucharist to be the flesh of our Saviour Jesus Christ, which suffered for our sins, and which the Father, of His goodness, raised up again" (Letter to the Smyrnaeans, 8). (Note the use of "which", referring to "the flesh", not "who", which would refer to "our Saviour Jesus Christ".) St. Justin Martyr, ca. 150: "We call this food Eucharist; and no one else is permitted to partake of it, except one who believes our teaching to be true.... For not as common bread nor common drink do we receive these; but since Jesus Christ our Savior was made incarnate by the word of God and had both flesh and blood for our salvation, so too, as we have been taught, the food which has been made into the Eucharist by the Eucharistic prayer set down by Him, and by the change of which our blood and flesh is nourished, is both the flesh and the blood of that incarnated Jesus" (Jurgens §128). From St. Clement of Alexandria, ca. 202: "'Eat My Flesh.' He says, 'and drink My Blood.' The Lord supplies us with these intimate nutriments. He delivers over His Flesh, and pours out His Blood; and nothing is lacking for the growth of His children. O incredible mystery!" (Jurgens §408).
The Scriptures, too, are testimony by the early Christians. In 1 Cor 10:16, St. Paul states: "The chalice of benediction, which we bless, is it not the communion of the blood of Christ? And the bread, which we break, is it not the partaking of the body of the Lord?" In the next chapter, he draws the same association we find in the Didache and elsewhere, i.e. the need for purity in receiving the Eucharist. First, Paul narrates the meal with Jesus: (11:24) "And giving thanks, broke, and said: Take ye, and eat: this is my body, which shall be delivered for you: this do for the commemoration of me." Likewise with the chalice; then Paul states (11:27) "Therefore whosoever shall eat this bread, or drink the chalice of the Lord unworthily, shall be guilty of the body and of the blood of the Lord." So we find that the early letters and documents, as well as the letters that became Holy Scripture among Christians, appear strongly to affirm a belief in what is today called by many the Real Presence, a summary term that refers to the notion that Jesus Christ is "really, truly, and substantially present" in the Eucharist.
Christian documents show that this dogma was maintained with the passage of time. From Origen, c 244: "[W]hen you have received the Body of the Lord, you reverently exercise every care lest a particle of it fall..." (Jurgens §490). From St. Ephraim, ante 373: "Do not now regard as bread that which I have given you; but take, eat this Bread, and do not scatter the crumbs; for what I have called My Body, that it is indeed" (Jurgens §707). From St. Augustine, c 412: "He walked here in the same flesh, and gave us the same flesh to be eaten unto salvation. But no one eats that flesh unless first he adores it; and thus it is discovered how such a footstool of the Lord's feet is adored; and not only do we not sin by adoring, we do sin by not adoring" (Jurgens §1479a). At the Roman Council VI, 1079, Berengarius affirmed: "I, Berengarius, in my heart believe and with my lips confess that through the mystery of the sacred prayer and the words of our Redeemer the bread and wine which are placed on the altar are substantially changed into the true and proper and living flesh and blood of Jesus Christ, our Lord..." (Denziger [Dz] §355). In a discussion of the form of consecration (the word now used to refer to the blessing given by Jesus), Pope Innocent III states (1202) "For the species of bread and wine is perceived there, and the truth of the body and blood of Christ is believed and the power of unity and of love.... The form is of the bread and wine; the truth, of the flesh and blood..." (Dz §414-4). The dogma was affirmed repeatedly by the Roman Catholic Church and within Roman Catholic theology, e.g. at the Council of Lyon, A.D. 1274 (Dz §465); by Pope Benedict XII, 1341 (Dz §544); by Pope Clement VI, 1351 (Dz §574a); at the Council of Constance, 1418 (Dz §583); at the Council of Florence, 1439 (Dz §698); by Pope Julius III at the Council of Trent, 1551 (Dz §874); by Pope Benedict XIV, 1743 (Dz §1469); by Pope Pius VI, 1794 (Dz §1529); and by Pope Leo XIII, 1887 (Dz §1919), inter alia. Other examples can be found to flesh out any interim.
The Summa Theologiae, c 1270, is considered within the Roman Catholic Church to be the paramount expression of its theology, and as such offers a clear discussion of the Eucharist. "[F]or Christ is Himself contained in the Eucharist sacramentally. Consequently, when Christ was going to leave His disciples in His proper species, He left Himself with them under the sacramental species..." (III 73 5). "The presence of Christ's true body and blood in this sacrament cannot be detected by sense, nor understanding, but by faith alone, which rests upon Divine authority. Hence, on : 'This is My body which shall be delivered up for you,' Cyril says: 'Doubt not whether this be true; but take rather the Saviour's words with faith; for since He is the Truth, He lieth not.' Now this is suitable, first for the perfection of the New Law. For, the sacrifices of the Old Law contained only in figure that true sacrifice of Christ's Passion, according to : 'For the law having a shadow of the good things to come, not the very image of the things'" (III 75 1). "[S]ince Christ's true body is in this sacrament, and since it does not begin to be there by local motion, nor is it contained therein as in a place, as is evident from what was stated above (III 75 1 ad 2), it must be said then that it begins to be there by conversion of the substance of bread into itself" (III 75 4).
In this last example from the Summa one can observe, with the passage of time, attempts to explain exactly what does take place in the event now termed transubstantiation. It is frequently described as a continuation of the sacrifice that Jesus made at Calvary, with the difference that it is unbloody. Yet Catholics maintain that the belief in what occurs is unchanged since the origins of Christianity, and it is belief that Christian theology teaches is central: Jesus refers to faith, not to knowledge, in the Scriptures. For example, Jesus tells Simon that it is by faith, i.e. revealed by the Father, that he knows that Jesus is from the Father (). Jesus extols faith in verses , , , , , and in other places besides. St. Thomas quotes St. Cyril in emphasizing faith as a basis for understanding. St. Augustine writes, "I believe in order to understand" (quoted in CCC §158). Roman Catholic and Eastern Orthodox theology has always emphasized the belief that Jesus is truly, really, and objectively present in the Eucharist. Over time, the dogma was clarified and preserved, and presented consistently to catechumens.
Catholics believe Christ spoke literally when Christ said "eat my body" not only because John 6:54 uses word strictly literal for "eat or chewing" but also because in Semitic thought to "eat flesh" in figurative language means to calumniate, revile, attack speak of someone not present (as in the Quran) or insult someone unjustly." Evidence of this is shown in both New and Old Testament in Micah 3:3, Psalm 27:1-2, Isaiah 9:18-21, Isaiah 49:26 and Revelation 17:6,16. All use the expression to "eat flesh" and some "drink blood" all uses are clearly negative, whether interpreted literally or figuratively. In brief, if Christ spoke to figuratively "eat my flesh" he would be instructing his followers to "hate" him.
Apart from the historical theology of the Real Presence, many other aspects of the Eucharist have long historical roots that can be located in Church Fathers and Scripture. The Eucharist is a permanent sacrament, not merely a temporary change during the liturgical service. From St. Cyril of Alexandria, ca. A.D. 440: "I hear that they are saying that the mystical blessing does not avail unto sanctification, if some of [the Eucharistic species] be left over to another day. They are utterly mad who say these things; for Christ is not made different, nor is His holy body changed, but the power of the blessing and the life-giving grace is uninterrupted in Him" (Jurgens §2139). With the passage of time it was possible to clarify the nature of the actual event that the blessing incurs; Pope Innocent III in A.D. 1202 explained that "among the opinions mentioned that is judged the more probable which asserts that the water with the wine is changed into blood" in reference to the mingling of water with the wine at the Mass (Dz §416). By A.D. 1415 Pope Martin V affirmed that "the material substance of bread and ... wine [no longer] remain" (Dz §581), also addressed by St. Thomas in the Summa e.g. III 75 4 This can be seen to be but a clarification in observing the great care, from the earliest date, taken to preserve every particle of Eucharist, e.g. Tertullian, A.D. 211: "We take anxious care lest something of our Cup or Bread should fall upon the ground" (Jurgens §367). In other words, it was plainly assumed that the transformation of the Bread and Cup was total. Issues surrounding clarifications of this kind raise an important point: Catholic theology posits that a shepherd is necessary, and mandated by Jesus (Jn 21:15, 16, 17) in a thrice-repeated statement to "Feed my lambs/sheep": St. Clement I, ca. A.D. 99: "Indeed you will give joy and gladness to us, if having become obedient to what we have written through the Holy Spirit, you will cut out the unlawful application of your zeal according to the exhortation which we have made in this epistle concerning peace and union" (Dz §41). The consecrating minister must be one who is correctly ordained, through that shepherd. Pope Innocent III, A.D. 1208: "[H]owever honest, religious, holy, and prudent anyone may be, he cannot nor ought he to consecrate the Eucharist nor to perform the sacrifice of the altar unless he be a priest, regularly ordained by a visible and perceptible bishop" (Dz §424). St. Ignatius of Antioch, ca. A.D. 110: "Let that be considered a valid Eucharist which is celebrated by the bishop, or by one whom he appoints" (Jurgens §65). The consecrated hosts are not merely changed permanently into Eucharist, but are due the worship of latria. Pope Julius III, A.D. 1551: "There is, therefore, no room left for doubt that all the faithful of Christ in accordance with a custom always received in the Catholic Church offer in veneration the worship of latria which is due to the true God, to this most Holy Sacrament" (Dz §878).
Some scholars note a similarity between the idea of feeding on the life-force of a mystical entity characteristic of the central rites of Graeco-Roman and Near-Eastern mystery religions, and claim that this is the context in which the acts and ordinances of Jesus and his apostles came to be memorialized. Although Christian authorities made no reference whatever to the purported mystical benefits of flesh-eating and blood-drinking that were proclaimed by proponents of cannibalism and of animal sacrifices among the mystery cults who promoted Omophagy and the ritual eating of raw flesh and organs of conquered leaders to absorb their power, they taught that the Christian "unbloody mysteries" (cf. Basil the Great, John Chrysostom, Council of Trent, Theses of Bonn) convey actual divine benefits. The scholars in question consider this comparison grounds for saying that Christianity presents the vestiges of ancient ritualistic cannibalism transferred into modern times.
This theory is rejected in Catholic Eucharistic theology. In fact, Christianity and the Eucharistic rite began not among people who believed in or practised the mystery religions, but within Judaism: the first Christians were all Jews. Paul's 57 AD First Letter to the Corinthians written little more than thirty years after the death of Jesus, and the Acts of the Apostles present the rite of "the Lord's supper" or "the breaking of bread" as dating from the very beginning of Christianity, when Christianity was still an entirely Jewish phenomenon, even before Gentiles, initially from among the "the God-fearing" (a term used for Gentiles who attended Jewish synagogue services but held back from becoming full-scale proselytes), were accepted as members of the Christian community. These writings, which are the earliest evidence about the rite of the Eucharist, thus indicate that these Christians believed they were continuing an already traditional reenactment of something that Jesus did and said at his last supper, and not performing a rite newly adapted from paganism, to which the same writings show they were strongly opposed. In fact, in , Paul cites precisely the Eucharistic rite as a reason for refusing to have anything to do with the idolatry and sacrifices of the pagans.
These and many more besides are points of spiritual theology that have been spoken by the saints and expounded in books for spiritual guidance. Belief in the Real Presence is key to the Roman Catholic conception of progression in prayer life along the purgative way to the illuminative and unitive ways (see prayer). The seven Sacraments, as a group, are "seven springs of life", springs in the progression toward union with God. "First of all, the initial sacrament that sows the seeds of eternity, Baptism.... The Eucharist feeds the holy growth with a substance which is none other than the very substance of the Son of God and the Son of man, the sovereign food of the divine life and of the human life in the Christian, since Jesus Christ has the fullness of the divine life and the human life.... The sacraments produce sacramental grace. What is this grace? It is a right, founded on sanctifying grace, and in virtue of which I can demand and receive at the proper time the help of actual grace.... If only I knew how to preserve these rights and to fall back upon them! Assuredly, if God gives them me, it is not for me to neglect them" (Tissot). Thus, through the twentieth century, Roman Catholic theology and spirituality yet teaches us that Jesus Christ in the Eucharist has meaning for us as individuals, a theme elaborated especially well by Dietrich von Hildebrand in Transformation in Christ.
Many prayers exist within Roman Catholic spiritual life, reflecting on the dogma of the Eucharist. From St. Thomas: Sit, Jesu dulcissime, sacratissimum Corpus tuum et Sanguis, dulcedo et suavitas animae meae,... (Sweetest Jesus, Body and Blood most holy, be the delight and pleasure of my soul...). Also: "Not through any merit of my own, but only through the goodness of Your mercy, You have considered me — a sinner, a useless servant — worthy to be nourished with the precious Body and Blood of Your Son, our Lord Jesus Christ." The Pater Noster contains the important line, "Give us this day our daily bread." Here the word "daily" is used to translate the Greek word epiousios. But "daily bread" can also be translated "supersubstantial bread" (as found in some Bible translations and in some prayers such as the "Prayer of St. Bonaventure" which begins: "Pierce, O most sweet Lord Jesus, my inmost soul..."). The Catholic Mass is offered daily, as are Eastern Orthodox communions. The active liturgical life of the Catholic faith is a key element in the theology of the Eucharist. At the Mass, it is prayed, Perceptio Corporis tui, Domine Jesu Christe, quod ego indignus sumere praesumo, non mihi proveniat in judicium et condemnationem: sed pro tua pietate prosit mihi ad tutamentum mentis ot corporis, et ad medelam percipiendam... essentially meaning, 'though I am unworthy, I presume to receive Thy Body; may it not turn to my judgment and condemnation'. (The Mass is available in Latin in hundreds of locations worldwide.) The daily bread in this prayer given by Jesus is a reference to the Eucharist according to many Church Fathers including St. Augustine, St. John Chrysostom, St. Jerome, and St. Cyprian of Carthage who in A.D. 251 wrote: "As the prayer continues, we ask and say, 'Give us this day our daily bread.' ... And we ask that this bread be given us daily, so that we who are in Christ and daily receive the Eucharist as the food of salvation, may not, by falling into some more grievous sin and then in abstaining from communicating, be withheld from the heavenly Bread, and be separated from Christ's Body. ... He Himself warns us... (Jn 6:54)" (Jurgens §559). Cyprian again: "We can understand this petition [give us this day our daily bread] in a spiritual and in a literal sense. For in the divine plan both senses may help toward our salvation. For Christ is the bread of life; this bread does not belong to everyone, but is ours alone. When we say, our Father, we understand that he is the father of those who know him and believe in him. In the same way we speak of our daily bread, because Christ is the bread of those who touch his body" (Liturgy of the Hours, 1975, Vol. III, Eleventh Week, Thursday, Office of Readings, Second Reading, emphases added). From the very earliest Church, it is clear that the Pater Noster refers to the Eucharist in conjunction with traditional Christian belief (faith) that it is the body and blood of Jesus Christ.