Rorate Caeli Dei altare se verteret...

If it is obviously true that a priest receives his priesthood so as to serve at the altar and that he enters upon this office by offering the Eucharistic Sacrifice, then it is equally true that for as long as he lives as God's minister, the Eucharistic Sacrifice will be the source and origin of the holiness that he attains and of the apostolic activity to which he devotes himself. All of these things came to pass in the fullest possible way in the case of St. John Vianney.

For, if you give careful consideration to all of the activity of a priest, what is the main point of his apostolate if not seeing to it that wherever the Church lives, a people who are joined by the bonds of faith, regenerated by holy Baptism and cleansed of their faults will be gathered together around the sacred altar? It is then that the priest, using the sacred power he has received, offers the divine Sacrifice in which Jesus Christ renews the unique immolation which He completed on Calvary for the redemption of mankind and for the glory of His heavenly Father. It is then that the Christians who have gathered together, acting through the ministry of the priest, present the divine Victim and offer themselves to the supreme and eternal God as a "sacrifice, living, holy, pleasing to God." There it is that the people of God are taught the doctrines and precepts of faith and are nourished with the Body of Christ, and there it is that they find a means to gain supernatural life, to grow in it, and if need be to regain unity. And there besides, the Mystical Body of Christ, which is the Church, grows with spiritual increase throughout the world down to the end of time.

It is only right and fitting to call the life of St. John Vianney a priestly and pastoral one in an outstanding way, because he spent more and more time in preaching the truths of religion and cleansing souls of the stain of sin as the years went by, and because he was mindful of the altar of God in each and every act of his sacred ministry!

It is true of course that the holy Curé's fame made great crowds of sinners flock to Ars, while many priests experience great difficulty in getting the people committed to their care to come to them at all, and then find that they have to teach them the most elementary truths of Christian doctrine just as if they were working in a missionary land.

But as important and sometimes as trying as these apostolic labors may be, they should never be permitted to make men of God forget the great importance of the goal which they must always keep in view and which St. John Vianney attained through dedicating himself completely to the main works of the apostolic life in a tiny country church. 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."

Pope Blessed John XXIII
Sacerdotii Nostri Primordia