The Heidelberg Catechism: Lord’s Day 33
88. Question: What is the true repentance or conversion of man?
Answer: It is the dying of the old nature and the coming to life of the new.[1]
[1] Rom. 6:1-11; I Cor. 5:7; II Cor. 5:17; Eph. 4:22-24; Col. 3:5-10.
89. Question: What is the dying of the old nature?
Answer: It is to grieve with heartfelt sorrow that we have offended God by our sin, and more and more to hate it and flee from it.[1]
[1] Ps. 51:3, 4, 17; Joel 2:12, 13; Rom. 8:12, 13; II Cor. 7:10.
90. Question: What is the coming to life of the new nature?
Answer: It is a heartfelt joy in God through Christ,[1] and a love and delight to live according to the will of God in all good works.[2]
[1] Ps. 51:8, 12; Is. 57:15; Rom. 5:1; 14:17. [2] Rom. 6:10, 11; Gal. 2:20.
91. Question: But what are good works?
Answer: Only those which are done out of true faith,[1] in accordance with the law of God,[2] and to His glory,[3] and not those based on our own opinion or on precepts of men.[4]
[1] Joh. 15:5; Rom. 14:23; Heb. 11:6. [2] Lev. 18:4; I Sam. 15:22; Eph. 2:10. [3] I Cor. 10:31. [4] Deut. 12:32; Is. 29:13; Ezek. 20:18, 19; Matt. 15:7-9.