From the Heidelberg Catechism for the Lord’s Day, August 18

88. In how many things does true repentance or conversion consist?
In two things: the dying of the old man, and the making alive of the new.

89. What is the dying of the old man?
Heartfelt sorrow for sin, causing us to hate and turn from it always more and more.

90. What is the making alive of the new man?
Heartfelt joy in God through Christ, causing us to take delight in living according to the will of God in all good works.

91. What are good works?
Those only which proceed from true faith, and are done according to the Law of God, unto His glory, and not such as rest on our own opinion or the commandments of men.