Lord's Day 28

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?
A.  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.1

Q. 76.  What is it then to eat the crucified body and drink the shed blood of Christ?
A.  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;2 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;3 so that we, though Christ is in heaven and we on earth,4 are notwithstanding flesh of his flesh, and bone of his bone;5 and that we live and are governed forever by one Spirit, as members of the same body are by one soul.6

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?
A.  In the institution of the supper, which is thus expressed:7 The Lord Jesus, the same night in which he was betrayed, took bread, and when he had given thanks, he brake it, and said: Take, 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;8 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.9
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.10