How does keeping the Sabbath help us to perform other religious duties better? A spiritual observance of the Sabbath day helps to keep us in touch with God. When we are really in communion with God, all other religious duties can be performed more earnestly and willingly. But if we neglect the Sabbath, our communion with God will be weakened, and we will be likely also to neglect other duties.

J. G. Vos, The Westminster Larger Catechism: A Commentary, 337.