For the Christian, Sunday is above all an Easter celebration, wholly illumined by the glory of the Risen Christ. It is the festival of the "new creation". Yet, when understood in depth, this aspect is inseparable from what the first pages of Scripture tell us of the plan of God in the creation of the world. It is true that the Word was made flesh in "the fullness of time" (Gal 4:4); but it is also true that, in virtue of the mystery of his identity as the eternal Son of the Father, he is the origin and end of the universe. As John writes in the Prologue of his Gospel: "Through him all things were made, and without him was made nothing that was made" (1:3). Paul too stresses this in writing to the Colossians: "In him all things were created, in heaven and on earth, visible and invisible .... All things were created through him and for him" (1:16). This active presence of the Son in the creative work of God is revealed fully in the Paschal Mystery, in which Christ, rising as "the first fruits of those who had fallen asleep" (1 Cor 15:20), established the new creation and began the process which he himself will bring to completion when he returns in glory to "deliver the kingdom to God the Father ..., so that God may be everything to everyone" (1 Cor 15:24,28).
Already at the dawn of creation, therefore, the plan of God implied Christ's "cosmic mission". This Christocentric perspective, embracing the whole arc of time, filled God's well-pleased gaze when, ceasing from all his work, he "blessed the seventh day and made it holy" (Gn 2:3). According to the Priestly writer of the first biblical creation story, then was born the "Sabbath", so characteristic of the first Covenant, and which in some ways foretells the sacred day of the new and final Covenant. The theme of "God's rest" (cf. Gn 2:2) and the rest which he offered to the people of the Exodus when they entered the Promised Land (cf. Ex 33:14; Dt 3:20; 12:9; Jos 21:44; Ps 95:11) is re-read in the New Testament in the light of the definitive "Sabbath rest" (Heb 4:9) into which Christ himself has entered by his Resurrection. The People of God are called to enter into this same rest by persevering in Christ's example of filial obedience (cf. Heb 4:3-16).