by the Committee on Doctrine of the USCCB 

 The Lord Jesus, on the night before He suffered on the cross, shared one last meal with His disciples. During this meal our Savior instituted the sacrament of His Body and Blood. He did this in order to perpetuate the sacrifice of the Cross throughout the ages and to entrust to the Church His Spouse a memorial of His death and resurrection 

 The Catholic Church professes that, in the celebration of the Eucharist, bread and wine become the Body and Blood of Jesus Christ through the power of the Holy Spirit and the instrumentality of the priest. Jesus said: “I am the living bread that came down from heaven; whoever eats this bread will live forever; and the bread that I will give is my flesh for the life of the world… For my flesh is true food, and my blood is true drink” (Jn 6:51-55). The whole Christ is truly present, body, blood, soul, and divinity, under the appearances of bread and wine—the glorified Christ who rose from the dead after dying for our sins. This is what the Church means when she speaks of the “Real Presence” of Christ in the Eucharist. This presence of Christ in the Eucharist is called “real” not to exclude other types of His presence as if they could not be understood as real (Catechism, no. 1374). The risen Christ is present to His Church in many ways, but most especially through the sacrament of His Body and Blood. 

 What does it mean that Jesus Christ is present in the Eucharist under the appearances of bread and wine? How does this happen? The presence of the risen Christ in the Eucharist is an inexhaustible mystery that the Church can never fully explain in words. We must remember that the triune God is the creator of all that exists and has the power to do more than we can possibly imagine. As St. Ambrose said: “If the word of the Lord Jesus is so powerful as to bring into existence things which were not, then a fortiori, those things which already exist, can be changed into something else” (De Sacramentis, IV, 5-16). God created the world in order to share His life with persons who are not God. This great plan of salvation reveals a wisdom that surpasses our understanding. But we are not left in ignorance: for out of His love for us, God reveals His truth to us in ways that we can understand through the gift of faith and the grace of the Holy Spirit dwelling in us. We are thus enabled to understand at least in some measure what would otherwise remain unknown to us, though we can never completely comprehend the mystery of God. 

 Why does Jesus give himself to us as food and drink? 

 Jesus gives himself to us in the Eucharist as spiritual nourishment because He loves us. God’s whole plan for our salvation is directed to our participation in the life of the Trinity, the communion of Father, Son, and Holy Spirit. By eating the Body and drinking the Blood of Christ in the Eucharist, we become united to the person of Christ through His humanity. “Whoever eats my flesh and drinks my blood remains in me and I in him” (Jn 6:56). In being united to the humanity of Christ, we are at the same time united to His divinity. Our mortal and corruptible natures are transformed by being joined to the source of life. “Just as the living Father sent me and I have life because of the Father, so also the one who feeds on me will have life because of me” (Jn 6:57). By being united to Christ through the power of the Holy Spirit dwelling in us, we are drawn up into the eternal relationship of love among the Father, the Son, and the Holy Spirit. As Jesus is the eternal Son of God by nature, so we become sons and daughters of God by adoption through the sacrament of Baptism. Through the sacraments of Baptism and Confirmation (Chrismation), we are temples of the Holy Spirit, who dwells in us, and by His indwelling we are made holy by the gift of sanctifying grace. The ultimate promise of the Gospel is that we will share in the life of the Holy Trinity. The Fathers of the Church called this participation in the divine life “divinization” (theosis). In this we see that God does not merely send us good things from on high; instead, we are brought up into the inner life of God, the communion among the Father, the Son, and the Holy Spirit. In the celebration of the Eucharist (which means “thanksgiving”) we give praise and glory to God for this sublime gift. 

 Does one receive the whole Christ if one receives Holy Communion under a single form? 

 Yes. Christ Jesus, our Lord and Savior, is wholly present under the appearance either of bread or of wine in the Eucharist. Furthermore, Christ is wholly present in any fragment of the consecrated Host or in any drop of the Precious Blood. Nevertheless, it is especially fitting to receive Christ in both forms during the celebration of the Eucharist. This allows the Eucharist to appear more perfectly as a banquet, a banquet that is a foretaste of the banquet that will be celebrated with Christ at the end of time when the Kingdom of God is established in its fullness (Eucharisticum Mysterium, no. 32).