From R.C. Sproul at Ligonier Ministries:
The church is our mother, but it is Christ’s bride. In this role, we are the objects of Christ’s affection. We, corporately, are His beloved. Stained and wrinkled, in ourselves we are anything but holy. When we say that the church is holy or refer to her as “holy mother church,” we do so with the knowledge that her holiness is not intrinsic but derived and dependent upon the One who sanctifies her and covers her with the cloak of His righteousness.
As the sensitive husband shelters his wife and in a chivalrous manner lends her his coat when she is chilled, so we are clad from on high by a husband who stops at nothing to defend, protect, and care for His betrothed. His is the ultimate chivalry, a chivalry that no upheaval of earthly custom can eradicate or make passé. This chivalry is not dead because it cannot die.
The bride of Christ is soiled but will one day be presented spotless to the Father by the Son who bought her, who loves her, and who intercedes for her every day. If we love Christ, we must also love His bride. If we love Christ, we must love His church.