278. Ecumenical endeavor in shrines dedicated to Our Lady pose special considerations. At a supernatural level, Our Lady, who gave birth to our Saviour and was the first and perfect disciple, played an important role in promoting unity and concord among the disciples of the Lord. Hence the Church refers to her as the Mater unitatis (Cf. Collectio missarum de Beata Maria Virgine, Form. 38: “Sancta Maria Mater Unitatis”; St. Augustine, Sermo 192, 2: PL 38, 1013; Paul VI, Homily on the Feast of the Presentation of Our Lord in the Temple, (2.2.1965), in Insegnamenti di Paolo VI, III (1965), Tipografia Polyglotta Vaticana, Città del Vaticano 1966, p. 68; John Paul II, Homily at the Shrine of Jasna Gora (4.6.1979) in Insegnamenti di Giovanni Paolo II, II/1 (19799, Libreria Editrice Vaticana, Città del Vaticano 1979, p. 1418; Angelus discourse (12.6.1988) in Insegnamenti di Giovanni Paolo II, XI/2 (1988), Libreria Editrice Vaticana, Città del Vaticano 1989, p. 1997). At the historical level, different interpretations of her role in the history of salvation have provoked divisions among Christians. On the other hand, it must be recognized that the Marian role is beginning to bear fruit in ecumenical dialogue.
The Directory on Popular Piety and the Liturgy is online at the Vatican site.