14. In the first place, therefore, Sunday is the day of rest because it is the day "blessed" by God and "made holy" by him, set apart from the other days to be, among all of them, "the Lord's Day".
In order to grasp fully what the first of the biblical creation accounts means by keeping the Sabbath "holy", we need to consider the whole story, which shows clearly how every reality, without exception, must be referred back to God. Time and space belong to him. He is not the God of one day alone, but the God of all the days of humanity.
Therefore, if God "sanctifies" the seventh day with a special blessing and makes it "his day" par excellence, this must be understood within the deep dynamic of the dialogue of the Covenant, indeed the dialogue of "marriage". This is the dialogue of love which knows no interruption, yet is never monotonous. In fact, it employs the different registers of love, from the ordinary and indirect to those more intense, which the words of Scripture and the witness of so many mystics do not hesitate to describe in imagery drawn from the experience of married love.
15. All human life, and therefore all human time, must become praise of the Creator and thanksgiving to him. But man's relationship with God also demands times of explicit prayer, in which the relationship becomes an intense dialogue, involving every dimension of the person. "The Lord's Day" is the day of this relationship par excellence when men and women raise their song to God and become the voice of all creation.
This is precisely why it is also the day of rest. Speaking vividly as it does of "renewal" and "detachment", the interruption of the often oppressive rhythm of work expresses the dependence of man and the cosmos upon God. Everything belongs to God! The Lord's Day returns again and again to declare this principle within the weekly reckoning of time. The "Sabbath" has therefore been interpreted evocatively as a determining element in the kind of "sacred architecture" of time which marks biblical revelation.(13) It recalls that the universe and history belong to God; and without a constant awareness of that truth, man cannot serve in the world as co-worker of the Creator.