Q. 75. How art thou admonished and assured in the Lord’s Supper, that thou art a partaker of that one sacrifice of Christ, accomplished on the cross, and of all His benefits?
Thus: That Christ has commanded me and all believers, to eat of this broken bread, and to drink of this cup, in remembrance of Him, adding these promises: first, that His body was offered and broken on the cross for me, and His blood shed for me, as certainly as I see with my eyes, the bread of the Lord broken for me, and the cup communicated to me; and further, that He feeds and nourishes my soul to everlasting life, with His crucified body and shed blood, as assuredly as I receive from the hands of the minister, and taste with my mouth the bread and cup of the Lord, as certain signs of the body and blood of Christ.
 Matthew 26:26–28; Mark 14:22–24; Luke 22:19–20; 1 Corinthians 10:16–17 and 11:23–25.
Q. 76. What is it then to eat the crucified body, and drink the shed blood of Christ?
It is not only to embrace with a believing heart all the sufferings and death of Christ, and thereby to obtain the pardon of sin, and life eternal;  but also, besides that, to become more and more united to His sacred body, by the Holy Ghost, who dwells both in Christ and in us; so that we, though Christ is in heaven and we on earth, are notwithstanding “Flesh of his flesh, and bone of his bone”; and we live, and are governed forever by one spirit, as members of the same body are by one soul.
 John 6:35, 40, 47–48, 50–51, 53–54;  John 6:55–56;  Acts 3:21 and 1:9–11; 1 Corinthians 11:26;  Ephesians 5:29–32; 1 Corinthians 6:15, 17, 19; 1 John 3:24;  John 6:56–58; Ephesians 4:15–16.
Q. 77. Where has Christ promised that He will as certainly feed and nourish believers with His body and blood, as they eat of this broken bread, and drink of this cup?
In the institution of the supper, which is thus expressed: “The Lord Jesus, the same night in which he was betrayed, took bread, and when he had given thanks, he brake it, and said: eat, this is my body, which is broken for you; this do in remembrance of me. After the same manner also he took the cup, when he had supped, saying: this cup is the new testament in my blood; this do ye, as often as ye drink it, in remembrance of me. For, as often as ye eat this bread, and drink this cup, ye do show the Lord’s death till he come.” This promise is repeated by the holy Apostle Paul, where he says: “The cup of blessing which we bless, is it not the communion of the blood of Christ? The bread which we break, is it not the communion of the body of Christ? For we, being many, are one bread and one body; because we are all partakers of that one bread.”
 1 Corinthians 11:23; Matthew 26:26; Mark 14:22; Luke 22:19;  Exodus 24:8; Hebrews 9:20;  Exodus 13:9; 1 Corinthians 11:26;  1 Corinthians 10:16–17.
It is interesting to note that the doctrine of the Lord’s Supper is treated more extensively than any other doctrine in the Heidelberg Catechism. The reason for this apparently disproportionate emphasis is in the fact that during the time of the Reformation, the doctrine of the Lord’s Supper was so greatly distorted under the papacy that when the Protestants seceded, they had difficulty defining what is right. Rome believes that the bread and wine become the actual flesh and blood of Christ after they are consecrated. Zwingli swung to the other end and claimed that Christ is not really present in any special way at the Supper. Luther reacted against what he perceived to be extremism and declared Zwingli to be having a different spirit. Calvin, on the other hand, struck a middle ground, teaching that Christ is really present, though not corporeally in the elements, and that when we partake of the elements, we are nourished spiritually, whereas one who partakes unworthily partakes poisons to his own soul. The Heidelberg Catechism, quite obviously, is based on Calvin’s viewpoint.
Heidelberg Catechism >