"The Church draws her life from the Eucharist.” With these words, Pope Saint John Paul II began his 2003 encyclical Ecclesia de Eucharistia. He continues,
The Pope goes on to explain how the communion we share in receiving the Eucharist builds up the communion of the Church. “The Eucharist thus appears as the culmination of all the sacraments in perfecting our communion with God the Father by the identification with his only-begotten Son through the working of the Holy Spirit” (EE 34). He calls the Eucharist “the supreme sacramental manifestation of communion in the Church” (EE 38) and says, “The Eucharist creates communion and fosters communion” (EE 40).
The Eucharist gives life to the Church by uniting Christians more perfectly with Christ and with one another. When we celebrate the Eucharistic sacrifice, receive the Eucharist in Holy Communion, or adore the Eucharistic presence of Christ in prayer, we are made the body of Christ by the body of Christ; we are constituted as the Church by our common participation in the Eucharist. The Eucharist creates communion. It brings us into communion with the whole Church and not only with those assembled. Pope Saint John Paul II writes,
When we bring Holy Communion to the sick, we extend to the sick persons the communion of our local churches. When a sick person who is confined in her home or in a hospital receives the Eucharist that is consecrated and offered in the worship of a local community, she is united to that church and shares in that assembly. But the Eucharist is never the celebration of one local community alone. Through Communion in our Eucharistic Lord, we receive Jesus’ presence completely and are perfected in our communion with the universal Church that is one, holy, catholic and apostolic. When our sick brothers and sisters receive Holy Communion, they are made one with Jesus, with the communion of Jesus’ believers in a particular church, and the Church universal that is Jesus’ body.
“The Church draws her life from the Eucharist” and the sick person draws her life from the Eucharist by which she shares in the communion of Christ and his Church. When ministers of Holy Communion bring that Blessed Sacraments to sick and suffering men and women confined in homes or in hospitals, we give them the Eucharist; but at the same time we give them the Church. Those sick persons are separated physically from the local community in which the Eucharistic sacrifice is celebrated. Nevertheless, by receiving the Eucharist, whether physically or spiritually, the sick person is brought into communion with the worship of the assembly and the communion of the Church universal. Though that sharing in the Eucharist and the communion it creates, the sick person in the hospital truly is “the image and true presence of the one, holy, catholic and apostolic Church”