The first striving of a priestly soul should be towards the closest union with the Divine Redeemer, towards the complete and humble acceptance of the precepts of Christian doctrine, and towards such a diligent application of those precepts at every moment of his life that his faith will illumine his conduct and his conduct will be a reflection of his faith. Led by the light of this virtue, let him keep his eyes fixed on Christ. Let him follow closely His Teaching, His actions and His example, convincing himself that it is not sufficient for him to accomplish the duties enjoined on the ordinary faithful. He must strive with ever increasing efforts to tend to perfection of life in keeping with the high dignity of the priesthood according to the warning of the Church: "Clerics must live both interiorly and exteriorly a holier life than lay people, and must excel them in giving an example of virtue and good deeds". The priestly life, since it arises from Christ should always and in everything be directed towards Him. Christ is the Word of God and did not disdain to assume human nature. He lived a life on earth in order to obey the will of the Eternal Father. He spread around Himself the fragrance of the lily. He lived in poverty, and "went about doing good and healing all". Finally, He offered Himself as a victim for the salvation of His brethren. That, beloved sons, is the summary of the wonderful life proposed to you. Strive with all your strength to reproduce it in yourselves and recall His words of exhortation: "For I have given you an example, that as I have done to you, so you also should do". (Papal Writings, Menti Nostrae, 23 September 1960).
St. Paul sets down as the basic principle of Christian perfection, the precept, "Put on the Lord Jesus Christ". Again if this precept applies to all Christians, it applies in a particular way to priests. But putting on Jesus Christ does not mean merely adapting one's mind to His doctrine; it means that a person enters upon a new life which, in order to shine with the splendor of Thabor, must first be conformed to the sufferings and trials of our Redeemer suffering on Calvary. This involves long and arduous labor, by which the soul is transformed to the state of victim, in order that it may participate intimately in the sacrifice of Christ. However, this arduous and assiduous labor is not to be accomplished through empty velleity, nor achieved through mere desires and promises; it must be an indefatigable and continuous exercise, which aims at a fruitful renovation of spirit; it must be an exercise of piety, which refers all things to the glory of God; it must be an exercise of penance, which tempers and checks the immoderate movements of the soul; it must be an act of charity, which inflames the soul with love of God and the neighbor, and which effectuates works of mercy; it must, in fine, be that active and ready willingness by which we strive and struggle to accomplish whatsoever is most perfect. (Papal Writings, Menti Nostrae, 23 September 1960).