"Though she is a harlot at times, she is our Mother."

     "As to the Church, where else shall we go, except to the Bride of Christ, one flesh with Christ?  Though she is a harlot at times, she is our Mother."

     Dorothy Day, "In peace is my bitterness most bitter," Catholic worker 33, no. 4 (January 1967):  2 (1-2).  I have checked this paragraph in the online edition against the original on microfilm and found it to be accurate.  Accurate as a quotation, that is, but not Catholic theology:
     Cf. Aidan Nichols, Figuring out the Church:  her marks, and her masters (San Francisco:  Ignatius Press, 2013), 51-52.  Having argued, following Maritain, that because "the Holy Spirit functions as a single Person in many P/persons" (Heribert Mühlen) such that "he constitute[s] her a corporate personality to which the attribute of holiness can at all times unconditionally be applied, even when individual persons, aggregated by the Spirit to her fellowship with Christ, continue to be active bearers of the sin of the world" (49), we must "distinguish the Church's own 'personality', sa personne, from her 'membership', son personnel" (50); that because "the Church has a personality  that is . . . always holy even when her individual members, weakening or failing in the spiritual warfare of the Christian life, are not" (50), sinful "Christians are . . . not acting qua members of the Church but qua those who are yet to become fully aligned with her" (51), he then proceeds as follows:

What should we make, then, of the celebrated (or notorious) patristic image of the Church as a 'chaste harlot', casta meretrix?  It is a phrase Origen of Alexandria coined and Saint Hilary of Potiers turned into Latin [(H. U. von Balthasar, "Casta Meretrix," Explorations in theology, vol. 2:  Spouse of the Word (San Francisco:  Ignatius Press, 1991), 193-228)].  Is this ancient (ante-Nicene) image of the chaste prostitute simply contradicted by the later affirmation Credo in . . . sanctam . . . Ecclesiam of the Creed of Nicaea-Constantinople?  No, it is not 'simply contradicted', because the holiness that qualifies the Church as a personality is always repentant holiness, and it is this truth that the chaste harlot image brings out.  When we commit sins, we never do so precisely as members of the Church.  But when we repent of our sins, when we become penitent, we do so as members of the Church such that the Church herself can be said to be penitent in us.  Indeed, the Church can be said to be penitent for all her sinful members, even for those who are not at the present time actually penitent, . . .  

and "That act [of vicarious repentance] . . . is . . . the dynamic foundation of the Church's personalité."  Cf. St. Bernard of Clairvaux.
     Cf. Philip Berrigan, as quoted by Gary Wills:  "Mother Church is a whore—but she is still our mother" (The New York review of books 64, no. 7 (April 20, 2017):  66 (65-66).
     For one strong position on the holiness of the Church, see Jacques Maritain, The peasant of the Garonne (19680, pp. 174-189.

     Apparently, though, von Balthasar, in his essay "Casta meretrix" (1960), "affirmed that the church sins precisely as the church, and not merely as individual members."  For the argument, see Stephen D. Lawson, "The apostasy of the church and the cross of Christ: Hans Urs von Balthasar on the mystery of the church as casta meretrix," Modern theology 36, no. 2 (April 2020):  259-280.  See also Wolfgang Beinert, "Ecclesia sancta et peccatrix:  (auch) ein ökumenische Problem," Catholica 68 (2014):  34-47, which I have on file, but haven't yet read.