Dominum et Vivificantem §62

⁶² The most complete sacramental expression of the "departure" of Christ through the mystery of the Cross and Resurrection is the Eucharist. In every celebration of the Eucharist his coming, his salvific presence, is sacramentally realized: in the Sacrifice and in Communion. It is accomplished by the power of the Holy Spirit, as part of his own mission. Through the Eucharist the Holy Spirit accomplishes that "strengthening of the inner man" spoken of in the Letter to the Ephesians. Through the Eucharist, individuals and communities, by the action of the Paraclete- Counselor, learn to discover the divine sense of human life, as spoken of by the Council: that sense whereby Jesus Christ "fully reveals man to man himself," suggesting "a certain likeness between the union of the divine persons, and the union of God's children in truth and charity." This union is expressed and made real especially through the Eucharist, in which man shares in the sacrifice of Christ which this celebration actualizes, and he also learns to "find himself...through a...gift of himself," through communion with God and with others, his brothers and sisters. For this reason the early Christians, right from the days immediately following the coming down of the Holy Spirit, "devoted themselves to the breaking of bread and the prayers," and in this way they formed a community united by the teaching of the Apostles. Thus "they recognized" that their Risen Lord, who had ascended into heaven, came into their midst anew in that Eucharisticcommunity of the Church and by means of it. Guided by the Holy Spirit, the Church from the beginning expressed and confirmed her identity through the Eucharist. And so it has always been, in every Christian generation, down to our own time, down to this present period when we await the end of the second Christian Millennium. Of course, we unfortunately have to acknowledge the fact that the Millennium which is about to end is the one in which there have occurred the great separations between Christians. All believers in Christ, therefore, following the example of the Apostles, must fervently strive to conform their thinking and action to the will of the Holy Spirit, "the principle of the Church's unity," so that all who have been baptized in the one Spirit in order to make up one body may be brethren joined in the celebration of the same Eucharist, "a sacrament of love, a sign of unity, a bond of charity!"