Proclamation is associated with the explicit preaching of the Gospel message. It is a kerygmatic function of the Church, part of our obligation to the Great Commission (cf. Matthew 28:19-20).
84. Sustaining Christian life as it does, Sunday has the additional value of being a testimony and a proclamation. As a day of prayer, communion and joy, Sunday resounds throughout society, emanating vital energies and reasons for hope. Sunday is the proclamation that time, in which he who is the Risen Lord of history makes his home, is not the grave of our illusions but the cradle of an ever new future, an opportunity given to us to turn the fleeting moments of this life into seeds of eternity. Sunday is an invitation to look ahead; it is the day on which the Christian community cries out to Christ, “Marana tha: Come, O Lord!” (1 Cor 16:22). With this cry of hope and expectation, the Church is the companion and support of human hope. From Sunday to Sunday, enlightened by Christ, she goes forward towards the unending Sunday of the heavenly Jerusalem, which “has no need of the sun or moon to shine upon it, for the glory of God is its light and its lamp is the Lamb” (Rev 21:23).
I like the contrast of grave and cradle. Self-delusion is a death. A cradle implies an incarnation, a making-flesh of a divine reality. A reminder that even the cycles of our planet and star will not be needed in the glory to come. And good thing, too. In about a hundred billion Sundays our planet will be uninhabitable, and in another few hundred billion Sundays, our star will be dead. Faith tells us Christ will live on, and there will be no need for physical cycles of day and night, as God will supply all we need to see.