10. In Christianity time has a fundamental importance. Within the dimension of time the world was created; within it the history of salvation unfolds, finding its culmination in the "fullness of time" of the Incarnation, and its goal in the glorious return of the Son of God at the end of time. In Jesus Christ, the Word made flesh, time becomes a dimension of God, who is himself eternal. With the coming of Christ there begin "the last days" (cf. Heb 1:2), the "last hour" (cf. 1 Jn 2:18), and the time of the Church, which will last until the Parousia.

From this relationship of God with time there arises the duty to sanctify time. This is done, for example, when individual times, days or weeks, are dedicated to God, as once happened in the religion of the Old Covenant, and as happens still, though in a new way, in Christianity. In the liturgy of the Easter Vigil the celebrant, as he blesses the candle which symbolizes the Risen Christ, proclaims: "Christ yesterday and today, the beginning and the end, Alpha and Omega, all time belongs to him, and all the ages, to him be glory and power through every age for ever". He says these words as he inscribes on the candle the numerals of the current year. The meaning of this rite is clear: it emphasizes the fact that Christ is the Lord of time; he is its beginning and its end; every year, every day and every moment are embraced by his Incarnation and Resurrection, and thus become part of the "fullness of time". For this reason, the Church too lives and celebrates the liturgy in the span of a year. The solar year is thus permeated by the liturgical year, which in a certain way reproduces the whole mystery of the Incarnation and Redemption, beginning from the First Sunday of Advent and ending on the Solemnity of Christ the King, Lord of the Universe and Lord of History. Every Sunday commemorates the day of the Lord's Resurrection.