Three facets of the apostolicity of the Eucharistic sacrament can be considered.

In the first place, it is apostolic because "it was entrusted by Jesus to the Apostles and has been handed down to us by them and by their successors. It is in continuity with the practice of the Apostles, in obedience to the Lord's command, that the Church has celebrated the Eucharist down the centuries" (Ecclesia de Eucharistia, n. 27). Its entrustment to the Church by Jesus and the Church's obedient response are the two pillars which have supported the celebration of the Eucharist down the ages, of which the Apostles are an integral part.

The words of n. 27 cited above should be taken in continuity with those other words in the previous chapter: "The Evangelists specify that it was the Twelve, the Apostles, who gathered with Jesus at the Last Supper (cf. Mt 26:20; Mk 14:17; Lk 22:14). This is a detail of notable importance, for the Apostles 'were both the seeds of the new Israel and the beginning of the sacred hierarchy' (Ad Gentes, n. 5).... The actions and words of Jesus at the Last Supper laid the foundations of the new messianic community, the People of the New Covenant" (Ecclesia de Eucharistia, n. 21). Thus, the Church continues what was begun with the Apostles, and so makes her beginnings constantly timely.

A second point of view leads to the assertion of this other truth: "The Eucharist is apostolic, for it is celebrated in conformity with the faith of the Apostles" (ibid., n. 27). Continuity with the Apostles' action is also continuity with their Eucharistic faith. This endurance of faith is part of the believing awareness of the early Church.

We find it witnessed to by St Paul when he explains to the Corinthians the significance of gathering to eat the Supper of the Lord: "I received from the Lord what I also delivered to you..." (I Cor 11:23), and of St Justin, in the middle of the second century: "We do not receive these things as ordinary food or drink; but... because this bread and wine have been 'eucharisted'... we have been taught that they are the flesh and blood of Jesus incarnate. Indeed, the Apostles, in the records they left us which are called Gospels, pass on the command that they themselves received" (St Justin, Apologia, I, 66, 2-3).

The Eucharist is a mystery of faith in which all the articles of the Apostolic Creed converge. If any of the truths concerning the Eucharistic Mystery were to be obscured, the whole installation of the Church would suffer a blow. The Holy Father therefore rightly points out that the apostolic faith in this sublime mystery "remains unchanged and it is essential for the Church that it remain unchanged" (Ecclesia de Eucharistia, n. 27).

The Eucharist is also apostolic because in it is expressed the fact that the Church "continues to be taught, sanctified and guided by the Apostles until Christ's return, through their successors in pastoral office" (ibid., n. 28, citing CCC, n. 857). Indeed, there is no Eucharist without ministerial priesthood. "The ministry of priests who have received the sacrament of Holy Orders... is in any event essential for validly linking the Eucharistic consecration to the sacrifice of the Cross and to the Last Supper" (Ecclesia de Eucharistia, n. 29).

To be truly Eucharistic, it is not enough that the assembly of the faithful gather to commemorate the paschal mystery and to invoke the gift of the Holy Spirit; it requires the action of one who can act "in specific sacramental identification with the eternal High Priest who is the author and principal subject of this sacrifice of his, a sacrifice in which, in truth, nobody can take his place" (ibid.). A sacramental identification of this kind can only be achieved through the sacrament of Holy Orders at the level of the priesthood. "On the other hand, the community is by itself incapable of providing an ordained minister. This minister is a gift which the assembly receives through episcopal succession going back to the Apostles" (ibid.).

The connection between the Eucharist, the ministerial priesthood and apostolic succession is a truth of faith, previously well explained by the Fourth Lateran Council and echoed in the Encyclical. In fact, that Council defined respect for the Sacrament of the altar in its profession of faith: "The Eucharistic mystery cannot be celebrated by anyone except a regularly-ordained priest, according to the powers of the Church which Jesus Christ himself conferred upon the Apostles and their successors" (DS 802; cf. p. 29).

Episcopal succession, which determines the very existence of the ordained priesthood and thus the Eucharist, dates back to the Apostles in a very precise way, that is, through "the uninterrupted sequence, from the very beginning, of valid episcopal ordinations" (Ecclesia de Eucharistia, n. 28). From the beginning, no Christian community has ever existed that organized itself on its own to guarantee the outpouring of the Holy Spirit, which makes Christ present in the Church through the apostolic ministry.

As the Second Vatican Council teaches, it was the Apostles themselves who passed on to their helpers their grace, the special outpouring of the Spirit with which they were endowed for the ministry through the imposition of hands, and this transmission has continued to the present day in episcopal consecration (cf. Lumen Gentium, n. 21).

Having stated these three aspects of the apostolicity of the Eucharist, the Holy Father reflects on certain practical consequences for the life of priests and of all the faithful, and at the same time, for the Church's pastoral activity.

The first consequence concerns relations with the Ecclesial Communities that came into being in the West in the 16th century, which are separated from the Catholic Church: "Especially because of the lack of the sacrament of Orders they have not preserved the genuine and total reality of the Eucharistic mystery" (Ecciesia de Eucharistia, n. 30, quoting Unitatis Redintegratio, n. 22). Differences in Eucharistic doctrine exist and cannot be overlooked, yet they might not have prevented the preservation of the substance of the Eucharist, as is the case with regard to Baptism. In fact, the Catholic Church recognizes the validity of Baptism, the first bond of communion in those Ecclesial Communities, even if important doctrinal divergences still exist on baptismal justification. Rather, with regard to the Eucharistic Mystery, the lack of the sacrament of Orders is crucial.

On the basis of their common Baptism, the Catholic faithful consider the members of these ecclesial communities as brothers and sisters, and reciprocal relations are constantly increasing in a crescendo of understanding and friendship. This cannot happen, however, at the cost of losing Eucharistic life. "The Catholic faithful, therefore, while respecting the religious convictions of these separated brethren, must refrain from receiving the communion distributed in their celebrations" (ibid., n. 30).

This is required by love of the truth and of Jesus himself: a love that is moved to seek intimate union with him through communion, truly receiving his body. "Similarly, it is unthinkable to substitute for Sunday Mass ecumenical celebrations of the Word or services of common prayer with Christians from the aforementioned Ecclesial Communities, or even participation in their own liturgical services" (ibid., n. 30). This would be to exchange a most precious Gift with articles of a decidedly lesser value.

The close, essential link between the Eucharist and the ministerial priesthood goes in both directions: the ordained priest is essential for there to be a Eucharistic celebration, and on the other hand, the Eucharist "is the principal and central raison d'etre of the sacrament of priesthood, which effectively came into being at the moment of the institution of the Eucharist" (ibid., n. 31).

Obviously, Eucharistic ministry does not exhaust the elements of priestly ministry, which includes other aspects not to be overlooked, be it the preaching of the Gospel or with regards to divine worship and guiding the Christian community. But the reference made to the Eucharistic Mystery is the most precious and elevated characteristic of ministerial priesthood and serves to define it.

This truth that concerns the essential core of the ordained priesthood also embraces the existential level of the priest's ministry. Thus: "If the Eucharist is the centre and summit of the Church's life, it is likewise the centre and summit of priestly ministry" (ibid.). From this principle many consequences may be deduced, and the Encyclical offers numerous suggestions.

Nonetheless, at this point, the Pope considers one that is undeniably practical and reasserts "how important it is for the spiritual life of the priest, as well as for the good of the Church and the world, that priests follow the Council's recommendation to celebrate the Eucharist daily.... In this way priests will be able to counteract the daily tensions which lead to a lack of focus and they will find in the Eucharistic Sacrifice — the true centre of their lives and ministry — the spiritual strength needed to deal with their different pastoral responsibilities. Their daily activity will thus become truly Eucharistic" (ibid., n. 31).

A conclusion is de rigeur. "The centrality of the Eucharist in the life and ministry of priests is the basis of its centrality in the pastoral promotion of priestly vocations" (ibid.). The Holy Father specifies two moments for its implementation: the prayer for priestly vocations during Mass, and the witness of the priests' painstaking care of the Eucharistic ministry. In fact, young men more easily accept the divine seed of the call to priesthood if they see and appreciate the Church's need for the Eucharist.

Christian communities which, in spite of having a sufficient number and variety of faithful to form a parish, do not have a priest to lead them, suffer a genuine "hunger" for the Eucharist (cf. ibid., nn. 32-33). In these circumstances, it is right that an effort be made somehow to remedy their privation, at least by organizing Sunday celebrations of prayer and listening to the Word of God. "But such solutions must be considered merely temporary, while the community awaits a priest" (ibid., 32).

It is not only the observation of the absence of a priest, but a real expectation of his presence: an active expectation, with more fervent prayers and the mobilization of all the resources needed for an adequate pastoral promotion of vocations. "In the Eucharist we have Jesus, we have his redemptive sacrifice, we have his resurrection, we have the gift of the Holy Spirit, we have adoration, obedience and love of the Father. Were we to disregard the Eucharist, how could we overcome our own deficiency?" (ibid., n. 60).