As we've been working through this study, I actually decided to skip Q80 with the boys. It definitely reflects the time it was written.
Question #80: How does the Lord's Supper differ from the Roman Catholic Mass?
Answer: The Lord's Supper declares to us that our sins have been completely forgiven through the one sacrifice of Jesus Christ which he himself finished on the cross once for all. It also declares to us that the Holy Spirit grafts us into Christ, who with his very body is now in heaven at the right hand of the Father where he wants us to worship him.
[But the Mass teaches that the living and the dead do not have their sins forgiven through the suffering of Christ unless Christ is still offered for them daily by the priests. It also teaches that Christ is bodily present in the form of bread and wine where Christ is therefore to be worshiped. Thus the Mass is basically nothing but a denial of the one sacrifice and suffering of Jesus Christ and a condemnable idolatry.]
(John 19:30; Heb. 7:27; 9:12, 25-26; 10:10-18, 1 Cor. 6:17; 10:16-17, Acts 7:55-56; Heb. 1:3; 8:1, Matt. 6:20-21; John 4:21-24; Phil. 3:20; Col. 3:1-3)
Q. and A. 80 was altogether absent from the first German edition of the Heidelberg Catechism (January 1563) but appeared in a shorter form in the second German edition (March 1563). The translation above is of the expanded text of the third German edition (ca. April 1563). Its strong tone reflects the setting in which the Catechism was written.
In response to a mandate from Synod 1998, the Christian Reformed Church’s Interchurch Relations Committee conducted a study of Q. and A. 80 and the Roman Catholic Mass. Based on this study, Synod 2004 declared that “Q. and A. 80 can no longer be held in its current form as part of our confession.” Synod 2006 directed that Q. and A. 80 remain in the CRC’s text of the Heidelberg Catechism but that the last three paragraphs be placed in brackets to indicate that they do not accurately reflect the official teaching and practice of today’s Roman Catholic Church and are no longer confessionally binding on members of the CRC.
Question #81: Who are to come to the Lord's table?
Answer: Those who are displeased with themselves because of their sins, but who nevertheless trust that their sins are pardoned and that their continuing weakness is covered by the suffering and death of Christ, and who also desire more and more to strengthen their faith and to lead a better life. Hypocrites and those who are unrepentant, however, eat and drink judgment on themselves (1 Cor. 10:19-22; 11:26-32).
Question #82: Are those to be admitted to the Lord's Supper who show by what they say and do that they are unbelieving and ungodly?
Answer: No, that would dishonor God's covenant and bring down God's anger upon the entire congregation. Therefore, according to the instruction of Christ and his apostles, the Christian church is duty-bound to exclude such people, by the official use of the keys of the kingdom, until they reform their lives (1 Cor. 11:17-32; Ps. 50:14-16; Isa. 1:11-17).