Heidelberg Catechism – Lord’s Day 44
Q. What is required in the tenth commandment?
A. That there should never enter our heart even the least inclination or thought contrary to any commandment of God, but that we should always hate sin with our whole heart and find satisfaction and joy in all righteousness.
Q. But can those who are converted to God keep these commandments perfectly?
A. No, for even the holiest of them make only a small beginning in obedience in this life. Nevertheless, they begin with serious purpose to conform not only to some, but to all the commandments of God.
Q. Why, then, does God have the ten commandments preached so strictly since no one can keep them in this life?
A. First, that all our life long we may become increasingly aware of our sinfulness, and therefore more eagerly seek forgiveness of sins and righteousness in Christ. Second, that we may constantly and diligently pray to God for the grace of the Holy Spirit, so that more and more we may be renewed in the image of God, until we attain the goal of full perfection after this life.