Q. 82 Where does Christ promise to nourish and refresh believers with his body and blood as surely as they eat this broken bread and drink this cup?
A. In the institution of the Lord’s Supper:
“The Lord Jesus, on the night he was betrayed, took bread, and when he had given thanks, he broke it and said, ‘This is my body, which is for you; do this in remembrance of me.’ In the same way, after supper he took the cup, saying, ‘This cup is the new covenant in my blood; do this, whenever you drink it, in remembrance of me.’ For whenever you eat this bread and drink this cup, you proclaim the Lord’s death until he comes.”
This promise is repeated by Paul in these words:
“Is not the cup of thanksgiving for which we give thanks a participation in the blood of Christ? And is not the bread that we break a participation in the body of Christ? Because there is one loaf, we, who are many, are one body, for we all partake of the one loaf.”
1 Cor. 11:23-26
1 Cor. 10:16-17