Actually Christ himself acts in every celebration of the Eucharist. The bishop or the priest represents him (in persona Christi).
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.
The Eucharist is the memorial of Christ’s Passover, the making present and the sacramental offering of his unique sacrifice, in the liturgy of the Church which is his Body. In all the Eucharistic Prayers we find after the words of institution a prayer called the anamnesis or memorial.hat way is Christ there when the Eucharist is celebrated?
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.
The Dogmatic Constitution, “Lumen Gentium” (3) discusses the sacrifice of Christ, as the work of our redemption
3. The Son, therefore, came, sent by the Father. It was in Him, before the foundation of the world, that the Father chose us and predestined us to become adopted sons, for in Him it pleased the Father to re-establish all things.(4) To carry out the will of the Father, Christ inaugurated the Kingdom of heaven on earth and revealed to us the mystery of that kingdom. By His obedience He brought about redemption. The Church, or, in other words, the kingdom of Christ now present in mystery, grows visibly through the power of God in the world. This inauguration and this growth are both symbolized by the blood and water which flowed from the open side of a crucified Jesus,(5) and are foretold in the words of the Lord referring to His death on the Cross: “And I, if I be lifted up from the earth, will draw all things to myself”.(6) As often as the sacrifice of the cross in which Christ our Passover was sacrificed, is celebrated on the altar, the work of our redemption is carried on, and, in the sacrament of the Eucharistic bread, the unity of all believers who form one body in Christ (8) is both expressed and brought about. All men are called to this union with Christ, who is the light of the world, from whom we go forth, through whom we live, and toward whom our whole life strains