This Is My Body
This article by Rodney Kleyn explicates Lord's Day 29 of the Heidelberg Catechism, addressing the Reformed understanding of Christ's presence in the Lord's Supper against Roman Catholic transubstantiation and other competing views. The piece explains how the bread and wine function as signs and seals that assure believers of their real spiritual participation in Christ's body and blood through the operation of the Holy Spirit, while maintaining that the elements themselves do not undergo physical transformation.
Lord's Day 29 Question 78. Do then the bread and wine become the very body and blood of Christ? Answer. Not at all; but as the water in baptism is not changed into the blood of Christ, neither is the washing away of sin itself, being only the sign and confirmation thereof appointed of God; so the bread in the Lord's supper is not changed into the very body of Christ; though agreeably to the nature and properties of sacraments, it is called the body of Christ Jesus. Question 79. Why then doth...
Full article available on sb.rfpa.org