Saint Francis of Borgia, while asking his novices some questions, noticed that some of them did not share his strong devotion to the Blessed Virgin.
He alerted the novice master, urging him to keep a vigilant eye on those young men.
Later, what the saint feared would happen did happen—all those novices lost the grace of their vocation.
Saint Philip Neri used to say to penitents while hearing confession: “My child, if you want to obtain the gift of perseverance, love and serve Our Lady! For one only falls and becomes lost when neglecting to call on her for help.”
Cf: Le Chapelet des enfants (The Children's Rosary)