Actually Christ himself acts in every celebration of the Eucharist. The BISHOP or the PRIEST represents him.

It is the CHURCH’S belief that the celebrant stands at the altar in persona Christi capitis (Latin = in the person of Christ, the Head). This means that priests do not merely act in Christ’s place or at his command; rather, on the basis of their ordination, Christ himself, as Head of the Church, acts through them

Christ is mysteriously but really present in the SACRAMENT of the EUCHARIST. As often as the CHURCH fulfills Jesus’ command, “Do this in remembrance of me” (1 Cor 11:24), breaks the bread and offers the chalice, the same thing takes place today that happened then: Christ truly gives himself for us, and we truly gain a share in him. The unique and unrepeatable sacrifice of Christ on the Cross is made present on the altar; the work of our redemption is accomplished. 

Every time the Church celebrates the EUCHARIST, she stands before the source from which she herself constantly springs anew. By “eating” the Body of Christ, the Church becomes the Body of Christ, which is just another name for the Church. In the sacrifice of Christ, who gives himself to us, body and soul, there is room for our whole life. We can unite everything—our work and our sufferings, our joys—with Christ’s sacrifice. If we offer ourselves in this way, we are transformed: We become pleasing to God and like good, nourishing bread for our fellowmen.

Again and again we grumble about the CHURCH, as though she were just an association of more or less good people. In reality the Church is what happens daily in a mysterious way at the altar. God gives himself to each one of us individually, and he wants to transform us through COMMUNION with him. Once we are transformed, we are supposed to transform the world. Everything else that the Church is besides that is secondary. 

Because God is truly present in the consecrated species of bread and wine, we must preserve the sacred gifts with the greatest reverence and worship our Lord and Redeemer in the Most Blessed Sacrament. 

If there are consecrated hosts left over after the celebration of Holy EUCHARIST, they are kept in sacred vessels in the tabernacle. Since the Most Blessed Sacrament is present in them, the TABERNACLE is one of the most venerable places in every church. We genuflect before any tabernacle. Certainly, anyone who is really following Christ will recognize him in the poorest of the poor and serve him in them. But he will also find time to spend in adoration before the tabernacle and offer his love to our Eucharistic Lord.

A Catholic Christian is obliged to attend Holy Mass on all Sundays and holy days of obligation. Anyone who is really seeking Jesus’ friendship responds as often as possible to Jesus’ personal invitation to the feast. 

Actually, for a genuine Christian, “Sunday duty” is just as inappropriate an expression as “kiss duty” would be for someone who was truly in love. No one can have a living relationship with Christ without going to the place where he is waiting for us. Therefore, from ancient times the celebration of Mass has been the “heart of Sunday” and the most important appointment in the week.

Someone who would like to receive Holy EUCHARIST must be Catholic. If he has a serious sin on his conscience, he must first make a confession. Before approaching the altar, one should be reconciled with his neighbors. 

Until a few years ago, the practice was to eat nothing for at least three hours before Mass; that was how people prepared to encounter Christ in Holy COMMUNION. Today the CHURCH recommends at least one hour of fasting. Another sign of reverence is to wear one’s finest clothing—after all, we have a rendezvous with the Lord of the world.

Every Holy COMMUNION unites me more deeply with Christ, makes me a living member of the Body of Christ, renews the graces that I received in Baptism and CONFIRMATION, and

fortifies me for the battle against sin.

Holy COMMUNION is the expression of the unity of the Body of Christ. To belong to the Catholic CHURCH, one must be baptized in her, share her faith, and live in union with her. It would be a contradiction if the Church were to invite to Communion people who do not (yet) share the faith and life of the Church. It would damage the credibility of the sign of the EUCHARIST.

Individual Orthodox Christians may ask to receive Holy Communion at a Catholic liturgy, because they share the Eucharistic faith of the Catholic Church, although their Church is not yet in full communion with the Catholic Church. In the case of members of other Christian “ecclesial communities” or denominations, Holy Communion may be administered to an individual if there is a grave necessity and evidence of faith in the Real Presence in the Eucharist. Joint celebrations of the Eucharist / Lord’s Supper by Catholics and Protestants are the goal and the wish of all ecumenical efforts; to anticipate them, however, without having established the reality of the Body of Christ in one faith and in the one Church is dishonest and therefore not allowed. Other ecumenical liturgies, in which Christians of various denominations pray together, are good and are also desired by the Catholic Church.

Jesus promised his disciples, and us with them, that we will one day sit at table with him. Therefore every Holy Mass is a “memorial of the blessed Passion” (Eucharistic Prayer I, called the Roman Canon), the fullness of grace, and a pledge of future glory.