Catechism of the Catholic Church
e. Para. 796: The unity of Christ and the Church, head and members of one Body, also implies the distinction of the two within a personal relationship. This aspect is often expressed by the image of bridegroom and bride. . . . The Lord referred to himself as the "bridegroom" (Mk 2:19). The Apostle speaks of the whole Church and of each of the faithful, members of his Body, as a bride "betrothed" to Christ the Lord so as to become but one spirit with him (Cf. Mt 22:1-14; 25:1-13; 1 Cor 6:15-17; 2 Cor 11:2). The Church is the spotless bride of the spotless Lamb (Cf. Rev 22:17; Eph 1:4; 5:27). "Christ loved the Church and gave himself up for her, that he might sanctify her" (Eph 5:25-26). He has joined her with himself in an everlasting covenant and never stops caring for her as for his own body . . . (Cf. Eph 5:29).
Para. 808: The Church is the Bride of Christ: he loved her and handed himself over for her. He has purified her by his blood and made her the fruitful mother of all God's children.