The Cathedral transformed into the Celestial City through the Divine Office

Canon François Villeman wrote: "The Divine Office with all its texts and ceremonies was instituted by the Church to provide God a cult that is agreeable to him, to preserve the majesty of the Christian religion, to elevate spirits to the contemplation of the Mysteries and to excite in us the fervor of holy devotion.  We should take especial care with its joyful observation and with the precision demanded by the great Apostle ...   It is thus that animated by the same spirit we will glorify God the Father and Our Lord Jesus Christ with the same heart and the same mouth; we will give a new brilliance to the Mother Church of this diocese, rendering it like the Celestial Jerusalem where the happy render their devotion to God with profound respect, united in an admirable order; we will augment the religion of the people and we will draw down upon us an abundance of grace and the blessings of heaven." 

The transformation of the material church into Heavenly Jerusalem is, of course, the theme of the key reading at the rite of consecration, Revelation 21: And I John saw the holy city, nes Jerusalem, coming down from God out of heaven, prepared as a bride adorned for her husband.  And I heard a great voice out of heaven saying Behold the Tabernacle of God is with men, and he will dwell with them, and they shall be his people....  And he [one of the seven angels] carried me away in the spirit to a great and high mountain, and showed me that great city, the holy Jerusalem, descending out of heaven from God.  Having the glory of God: and her light was like unto a stone most precious, even like a jasper stone, clear as crystal....