Ad Catholici Sacerdotii §85

⁸⁵ If, however, your work is to be blessed by God and produce abundant fruit, it must be rooted in holiness of life. Sanctity, as We said above, is the chief and most important endowment of the Catholic priest. Without it other gifts will not go far; with it, even supposing other gifts be meager, the priest can work marvels. We have the example of St. Joseph of Cupertino, and in times nearer to our own of that humble Cure d'Ars, St. John Mary Vianney, of whom We have already spoken; whom We have willed to set up before all parish priests as their model and heavenly Patron. Therefore with the Apostle of the Gentiles, We say to you: "Behold your vocation"; and beholding it, you cannot fail to value ever more highly the grace given to you in ordination and to strive to "walk worthily of the vocation in which you are called."