On the eve of the great feast of the Immaculate Conception of Mary let us reflect on the closing words of Pius XII’s Encyclical,‘Sacra Virginitas’, a golden key unlocking the best way to preserve and increase the virtue of virginity and chastity, which is to have a strong devotion to the Mother of God, who is the model of these virtues.
This total dependence on the Blessed Virgin Mary to practice perfect chastity is something that many persons would like to disregard, given their pride in imagining they are able to practice virtue by themselves as well as the influence they suffer from the errors of Protestantism.
“The eminent way to protect and nourish an unsullied and perfect chastity, as proven by experience time and again throughout the course of centuries, is solid and fervent devotion to the Virgin Mother of God. In a certain way all other helps are contained in this devotion. There is no doubt that whoever is sincerely and earnestly animated by this devotion is salutarily inspired to constant vigilance, to continual prayer, to receive the Sacraments of Penance and the Holy Eucharist. …
That virginity owes its origin to Mary is the testimony of Athanasius, (De virginitate, Museon, 42, 1929, p. 247) and Augustine clearly teaches, “The dignity of virginity began with the Mother of the Lord.” (Sermo 51, c. 16. n. 26, PL, 38, 348). Pursuing the ideas of Athanasius, Ambrose holds up the life of the Virgin Mary as the model of virgins:
“Imitate her, my daughters! … (De institutione virginis, c. 14, n. 87, PL 16, 328) Let Mary’s life be for you the very portrayal of virginity, for, from her, as though from a mirror, is reflected the beauty of chastity and the ideal of virtue. See in her the pattern of your life, for, in her, as in a model, manifest teachings of goodness show what you should correct, what you should copy and what you should preserve. … She is the image of virginity. For such was Mary that her life alone suffices for the instruction of all. …(De virginibus, lib. 2, c. 2, n. 6, PL 16 208, 210)
“Therefore, let holy Mary guide your way of life.” (Ibid., c.3, n. 19, PL 16, 211) Her grace was so great that it not only preserved in her the grace of virginity, but bestowed the grace of chastity upon those on whom she visited.” (Ibid., c. 7, n. 50, PL 16, 319)
How true is the saying of Ambrose: “Oh the richness of the virginity of Mary!’ (Ibid., c. 13, n. 81, PL 16, 319) …
But it is not enough, beloved sons and daughters, to meditate on the virtues of the Blessed Virgin Mary: With absolute confidence fly to her and obey the counsel of St. Bernard: “Let us seek grace and seek it through Mary.” (In nativitate B. Mariae Virginis, Sermo de acquaeductus, n. 8, PL 183, 441-442)
In a special way entrust to her during the Marian Year  the care of your spiritual life and perfection, imitating the example of Jerome who asserted: “My virginity is dedicated in Mary and to Christ.” (Epist. 22, n. 18, PL 22, 405)
of March 25, 1954, nn. 64-66.