1. “He who eats my flesh and drinks my blood has eternal life" (Jn 6:54). By instituting the Eucharist on the eve of his death, Christ wanted to give the Church a food that would nourish her continually and make her live his own life as the Risen One.
Long before the institution, Jesus had announced this unique meal. In Jewish worship there was no lack of sacred meals, which were eaten in the presence of God and which manifested the joy of divine favour. Jesus surpasses all this: now it is he, in his flesh and blood, who becomes the food and drink of humanity. In the Eucharistic meal, man feeds on God.
When, for the first time, Jesus announces this food, he arouses the amazement of his listeners, who fail to grasp such a lofty divine plan. Jesus therefore vigorously emphasised the objective truth of his words, affirming the necessity of the Eucharistic meal: "Truly, truly, I say to you, unless you eat the flesh of the Son of Man and drink his blood, you will not have life in you" (John 6: 53). This is not a purely spiritual meal, in which the expressions 'eating the flesh' of Christ and 'drinking his blood' would have a metaphorical meaning. It is a true meal, as Jesus emphatically states: "My flesh is true food and my blood true drink" (Jn 6:55).
Such food, moreover, is no less necessary for the development of divine life in the faithful than material food is for the maintenance and development of bodily life. The Eucharist is not a luxury offered to those who would like to live more intimately united to Christ: it is a requirement of Christian life. This requirement was understood by the disciples since, according to the testimony of the Acts of the Apostles, in the early days of the Church the "breaking of bread", the Eucharistic meal, was practised daily in the homes of the faithful "with joy and simplicity of heart" (Acts 2:46).
2. In the promise of the Eucharist, Jesus explains why this food is necessary: "I am the bread of life" he declares (Jn 6:48). "As the Father, who has life, has sent me and I live for the Father, so also he who eats of me will live for me" (John 6:57). The Father is the first source of life: he has given this life to the Son, who in turn communicates it to humanity. He who feeds on Christ in the Eucharist does not have to wait for the hereafter to receive eternal life: he already possesses it on earth, and in it he also possesses the guarantee of bodily resurrection at the end of the world: "He who eats my flesh and drinks my blood has eternal life, and I will raise him up at the last day" (Jn 6:54).
This guarantee of Resurrection comes from the fact that the flesh of the Son of Man given as food is his body in the glorious state of the Risen One. The listeners to the promise of the Eucharist had not grasped this truth: they thought that Jesus wanted to speak of his flesh in the state of his earthly life, and thus manifested great repugnance at the meal announced. The Master corrects their way of thinking, pointing out that it is the flesh of the Son of Man "ascended to where he was before" (Jn 6:62), that is, in the triumphant state of his ascension into heaven. This glorious body is filled with the life of the Holy Spirit, and it is in this way that it can sanctify the men who feed on it, and give them the pledge of eternal glory.
In the Eucharist, therefore, we receive the life of the risen Christ. For when the sacrifice is sacramentally performed on the altar, not only is the mystery of the Saviour's Passion and Death made present in it, but also the mystery of the Resurrection, in which the sacrifice finds its crowning glory. The Eucharistic celebration makes us participate in the redemptive offering, but also in the triumphant life of the risen Christ. This is the reason for the atmosphere of joy that characterises every Eucharistic liturgy. While commemorating the drama of Calvary, once marked by immense sorrow, the priest and the faithful rejoice in uniting their offering to that of Christ, because they know that they are at the same time living the mystery of the Resurrection, inseparable from this offering.
3. The life of the risen Christ is distinguished by its power and richness. The one who receives communion receives the spiritual strength needed to face all obstacles and trials while remaining faithful to his commitments as a Christian. He also draws from the Sacrament, as from an abundant spring, continuous streams of energy for the development of all his resources and qualities, in a joyful ardour that stimulates generosity.
In particular, he draws on the life-giving energy of charity. In the tradition of the Church, the Eucharist has always been considered and lived as the sacrament par excellence of unity and love. Already St Paul declares it: "Since there is one bread, we, though we are many, are one body; For we all partake of the one bread" (1 Cor 10:17).
The Eucharistic celebration brings together all Christians, whatever their differences, in a unanimous offering and meal in which all participate. It gathers them all into the equal dignity of brothers of Christ and sons of the Father; it invites them to respect, to mutual esteem, to mutual service. Communion also gives each person the moral strength needed to rise above reasons for division and opposition, to forgive wrongs received, to make a new effort in the direction of reconciliation and fraternal understanding.
Is it not, moreover, particularly significant that the precept of mutual love was formulated by Christ in its highest expression during the Last Supper, at the institution of the Eucharist? Every believer should remember this when approaching the Eucharistic table and strive not to contradict with his life what he celebrates in the mystery.
[Pope John Paul II, General Audience 8 June 1983]