Personal Holiness and the Mass
56. This should be kept in mind, in particular: whatever a priest may plan, resolve, or do to become holy, he will have to draw, for example and for heavenly strength, upon the Eucharistic Sacrifice which he offers, just as the Roman Pontifical urges: "Be aware of what you are doing; imitate what you hold in your hands."
58. This lofty aspect of doctrine is what the Church has in mind when, with maternal care, she invites her sacred ministers to devote themselves to asceticism and urges them to celebrate the Eucharistic Sacrifice with the greatest possible interior and exterior devotion. May not the fact that some priests fail to keep in mind the close connection that ought to exist between the offering of the Sacrifice and their own self-dedication be the reason why they gradually fall off from that first fervor they had at the time of their ordination? St. John Vianney learned this from experience and expressed it this way: "The reason why priests are remiss in their personal lives is that they do not offer the Sacrifice with attention and piety." And he, who in his lofty virtue, was in the habit of "offering himself as an expiation for sinners" (67) used to weep "when he thought of the unhappy priests who did not measure up to the holiness demanded by their office" (63)
59. Speaking as a Father, We urge Our beloved priests to set aside a time to examine themselves on how they celebrate the divine mysteries, what their dispositions of soul and external attitude are as they ascend the altar and what fruit they are trying to gain from it. They should be spurred to do this by the centenary celebrations that are being held in honor of this outstanding and wonderful priest, who drew such great strength and such great desire to dedicate himself "from the consolation and happiness of offering the divine victim." (69) May his prayers, which We feel sure they will have, bring a fullness of light and strength down upon Our beloved priests.
60. The wonderful examples of priestly asceticism and prayer that We have proposed for your consideration up to now, Venerable Brethren, also point clearly to the source of the pastoral skill and of the truly remarkable heavenly effectiveness of the sacred ministry of St. John M. Vianney. In this regard, Our predecessor of happy memory, Pius XII, gave a wise warning: "The priest should realize that the important ministry entrusted to him will be more fruitfully carried out, the more intimately he is united with Christ and led on by His spirit." (70) As a matter of fact, the life of the Cure of Ars offers one more outstanding argument in support of the supreme rule for apostolic labor that was laid down by Jesus Christ Himself: "Without me, you can do nothing." (71)