"Often, too, the Church is called the building of God. The Lord compared himself to the stone which the builders rejected, but which was made into the corner-stone. On this foundation the Church is built by the apostles and from it the Church receives solidity and unity. This edifice has many names to describe it: the house of God in which his family dwells; the household of God in the Spirit; the dwelling-place of God among men; and, especially, the holy temple. This temple, symbolized in places of worship built out of stone, is praised by the Fathers and, not without reason, is compared in the liturgy to the Holy City, the New Jerusalem. As living stones we here on earth are built into it. It is this holy city that is seen by John as it comes down out of heaven from God when the world is made anew, prepared like a bride adorned for her husband.
-- CCC 756
By her complete adherence to the Father's will, to his Son's redemptive work, and to every prompting of the Holy Spirit, the Virgin Mary is the Church's model of faith and charity. Thus she is a "preeminent and . . . wholly unique member of the Church"; indeed, she is the "exemplary realization" (typus) of the Church.
-- CCC 967