It is vitally important that worshipers understand the role of God’s law among us. God gives his law to us, not so that we can earn his favor by full obedience, for even those converted to God cannot obey this law perfectly. Heidelberg Catechism, Lord’s Day 44, Question and Answer 114 says, “In this life even the holiest have only a small beginning of this obedience.” Instead, says Heidelberg Catechism, Lord’s Day 2, Question and Answer 3, through this law “we come to know [our] misery.”
Yet in their new life of gratitude, God’s children “with all seriousness of purpose, do begin to live according to all, not only some, of God’s commandments” (Heidelberg Catechism, Lord’s Day 44, Question and Answer 114). They measure their good works of gratitude as “those which are done out of true faith, conform to God’s law, and are done for God’s glory” (Heidelberg Catechism, Lord’s Day 33, Question and Answer 91).
In other words, though Christ has fulfilled the law for us, “The truth and substance of these things remain for us in Jesus Christ…[and] we continue to use the witnesses drawn from the law and prophets to confirm us in the gospel and to regulate our lives with full integrity for the glory of God according to the will of God” (Belgic Confession, Article 25). Therefore, the Ten Commandments with explanation are included in the third section, “gratitude,” (Lord’s Days 34-44) of Heidelberg Catechism.