His great secret for attracting souls to Jesus

The mainspring of all his apostolic ministry, his great secret for drawing souls and giving them over to Jesus, is devotion to Mary. This devotion is the source of all his activity; the reason for all his confidence. And it would have been impossible for him to find a more telling weapon for the times in which he lived.

To Jansenism with its joyless austerity, its somber apprehensions, its proud depressions, he opposes the filial love of the devout servant of Mary; a love which is at once confident, ardent, expansive and effective for Mary who is the Refuge of Sinners, the Mother of Divine Grace, our life, our sweetness and our hope.

She is also our advocate. Placed as she is between God and the sinner, Mary is ever busy invoking the clemency of the judge in order to move Him to pity, and she is ever trying to overcome the obstinacy of the sinner.

The missioner was convinced of this part played by Mary, a conviction strengthened by his own experience, and so he used to say with picturesque simplicity “that a sinner had never resisted him once he held him by the scruff of the neck with his Rosary!”

Pius XII, Papal Allocution at the Canonization of Blessed Louis Marie Grignion de Montfort (July 21, 1947)