As the great website papalencyclicals.net has the text of the entire encyclical online, I'll only post the 'highlights' here but I urge you to go their website to read it in full.
" The Great Gift of the Priesthood
As our predecessors taught, especially Pius X and Pius XI, and as We referred to in the encyclicals Mystici Corporis and Mediator Dei, the priesthood is a great gift of the Divine Redeemer, Who, in order to perpetuate the work of redemption of the human race which He completed on the Cross, confided His powers to the Church which He wished to be a participator in His unique and everlasting Priesthood. The priest is like "another Christ" because he is marked with an indelible character making him, as it were, a living image of our Saviour. The priest represents Christ Who said "As the Father has sent me, I also send you";"he who hears you, hears me". Admitted to this most sublime ministry by a call from heaven, "he is appointed for men in the things pertaining to God, that he may offer gifts and sacrifices for sins".To him must come anyone who wishes to live the life of the Divine Redeemer and who desires to receive strength, comfort and nourishment for his soul; from him the salutary medicine must be sought by anyone who wishes to rise from sin and lead a good life. Hence all priests may apply to themselves with full right the words of the Apostle of the Gentiles: "We are God's helpers".
This lofty dignity demands from priests that they react to their exalted office with the strictest fidelity. Since they are destined to promote the glory of God on earth and to cherish and increase the Mystical Body of Christ, they must be outstanding by the sanctity of their lives in order that through them the "fragrance of Christ" may be spread everywhere.
The Fundamental Duty
Beloved sons, on the very day that you were raised to the sacerdotal dignity, the Bishop, in the name of God, solemnly pointed out to you your fundamental duty in the following words: "Understand what you do, imitate the things you deal with; and celebrating the mystery of the death of the Lord, strive to mortify in your members all vice and concupiscence. May your doctrine be the spiritual medicine for the people of God; let the fragrance of your life of virtue be an ornament of the Church of Christ; and by your preaching and example may you build the house, that is the family of God". Your life, which should be completely immune from sin, should be even more hidden with Christ in God than the lives of Christian layfolk. Advance then, thus adorned with that high virtue which your dignity demands, to the work of completing the redemption of man for which your priestly ordination has destined you.
This is the undertaking which you have freely and spontaneously assumed; be holy because, as you know, your ministry is holy.
PART I. SANCTITY OF LIFE
Perfection Consists in Fervent Charity
According to the teaching of the Divine Master, the perfection of Christian life consists especially in the love of God and of one's neighbor, a love that is fervent, devoted, and painstaking. If it has these qualities it can be said to embrace all virtues; and can rightly be called the "bond of perfection".In whatever circumstances a man is placed he should direct his intentions and his actions towards this end.
The Priest is Called to Perfection
However, the priest is bound to do this by his very office. By its very nature every priestly action necessarily tends to this end since the priest is called to this by divine vocation, destined for it by his divine office and confirmed by a divine grace. For he must cooperate with Christ, the only and eternal Priest; he must follow Him and imitate Him, Who during His life on earth had no other purpose than to bear witness to His most ardent love for His Father and to bestow on men the infinite treasures of His Heart.
IMITATION OF CHRIST
Intimate Union with JesusThe 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".
The Practice of Humility
The beginning of Christian perfection stems from humility. "Learn from Me, for I am meek and humble of heart". The consideration of the high dignity to which we are called by Baptism and Holy Orders and the knowledge of our own spiritual need ought to induce us to meditate on the words of Christ: "Without Me you can do nothing".
Distrust of Self
Let the priest not trust in his own strength nor be complacent in his own gifts nor seek the esteem and praise of men but let him imitate Christ, Who "did not come to be served but to serve", let him deny himself according to the teaching of the Gospel, detaching himself from the things of the earth in order to follow the Divine Master more easily and more readily. Whatever he has, whatever he is, is due to the goodness and power of God; if he wishes to glory in this let him remember the words of the Apostle of the Gentiles: "For myself I will glory in nothing save in my infirmities".
Immolation of the Will
The spirit of humility, illumined by faith, disposes the soul to the immolation of the will by means of obedience. Christ Himself established in the society He founded a legitimate authority which is a continuation of His own. Hence he who obeys the authorities of the church is obeying the Redeemer Himself.
The Necessity of Obedience
In an age like ours, in which the principle of authority is grievously disturbed, it is absolutely necessary that the priest, keeping the precepts of faith firmly in mind, should consider and duly accept this same authority, not only as the bulwark of the social and religious order, but also as the foundation of his own personal sanctification. While the enemies of God, with criminal astuteness, are trying to incite and solicit people's unruly passions, to make them rise up against the commands of Holy Mother Church, We wish to give due praise to, and animate with paternal encouragement that vast army of ministers of God, who, in order to manifest openly their Christian obedience and to preserve intact their fidelity to Christ and to the legitimate authority established by Him, "have been counted worthy to suffer disgrace for the name of Jesus",and not only disgrace, but persecutions and prison and even death.Celibacy
The priest has as the proper field of his activity everything that pertains to the supernatural life, since it is he who promotes the increase of this supernatural life and communicates it to the Mystical Body of Jesus Christ. Consequently, it is necessary that he renounce "the things of the world," in order to have care only for "the things of the Lord". And it is precisely because he should be free from preoccupation with worldly things to dedicate himself entirely to the divine service, that the Church has established the law of celibacy, thus making it ever more manifest to all peoples that the priest is a minister of God and the father of souls. By his law of celibacy, the priest, so far from losing the gift and duties of fatherhood, rather increases them immeasurably, for, although he does not beget progeny for this passing life of earth, he begets children for that life which is heavenly and eternal.
The more resplendent priestly chastity is, so much the more does the sacred minister become, together with Christ, "a pure victim, a holy victim, an immaculate victim".
In order carefully to preserve unstained this inestimable treasure of our chastity, it is suitable and necessary to be obedient to that exhortation of the Prince of Apostles, which we daily repeat in the Divine Office, "Be ye sober, and watch".
Vigilance and Prayer the Safeguards of Chastity
Yes, watch, beloved sons, because priestly chastity is exposed to so many dangers, whether by reason of laxity in public morals, or because of the allurements of vice which you find so easily seductive in these days, or, finally, because of that excessive liberty in relations between the sexes which at times dares to insinuate itself even into the exercise of the sacred ministry. "Watch and pray", mindful that your hands touch those things which are most holy, that you have been consecrated to God and are to serve Him alone. The very habit which you wear, reminds you that you should live not to the world, but to God. Therefore, trusting in the protection of the Virgin Mother of God, generously make every effort to preserve yourselves "clean, unstained, pure and chaste, as becomes the ministers of Christ and the dispensers of the mysteries of God."
Avoidance of Familiarity
To this end We deem it opportune to address to you a special exhortation as regards your direction of associations and sodalities of women, that you show yourselves as becomes a priest; avoid every familiarity; when you must give your services, give them in a way that is befitting sacred ministers. Moreover, in directing these associations, let your interest be confined to the demands of the sacred ministry.
Detachment from Worldly Possessions
Nor should you consider it sufficient to renounce earthly pleasures through chastity and to submit in generous obedience to your superiors; to these you must also unite daily a detachment of your hearts from riches and from the things of earth. Reverently take as your models those great saints of ancient and modern times who joined this essential detachment from material goods to a profound trust in Divine Providence and a most ardent priestly zeal; as a result, they produced works that are truly marvelous, confiding solely in God who, assuredly, is never found wanting in our needs. Even priests who do not make a profession of poverty by a special vow, must always be guided by the love of this virtue, a love that ought to show itself in the simplicity and modesty of their manner of life, in their living quarters, and in their generosity to the poor. Let them especially refrain from those economic enterprises which would impede the fulfillment of their pastoral duties, and lessen the respect which is due to them from the faithful. Since it is the office of the priest to spend every effort to obtain the salvation of souls, he must apply to himself those words of St. Paul, "I do not seek yours, but you".
The Priest a Model of All Virtues
Many things occur to Our mind which We might say if there were an opportunity here of giving a detailed treatment of all the virtues by which the priest should reproduce in himself as faithfully as possible the Divine Model, Jesus Christ. But We have chosen to concentrate Our attention on those things which seemed to be specially necessary in our times. As for other virtues, let it suffice that We now recall to your minds the words of that golden book, The Imitation of Christ, "The priest should be adorned with all the virtues, and give an example to others of a righteous life. Let his conversation be not according to the common and vulgar ways of men, but with the angels and with men that are perfect".
The Priest's Life a Life of Sacrifice
As the whole life of the Saviour was directed toward the sacrifice of Himself, so the life of the priest, which should reproduce in itself the image of Christ, ought also to be with Him, and through Him, and in Him, a pleasing sacrifice.
After the Example of Jesus on Calvary
Indeed, the sacrifice which the Lord made upon Calvary, hanging on the cross, was not only the immolation of His own Body; for He offered Himself, a Victim of expiation, as the Head of the human race and, therefore, "while commending His Spirit into the hands of the Father, He commends Himself to God as man, in order to commend to the Eternal Father all mankind".
. . . and in Holy Mass
The very same thing occurs in the Sacrifice of the Eucharist, which is the unbloody renewal of the Sacrifice of the Cross: Christ offers Himself to the Eternal Father for His glory and for our salvation. And in so far as He, the Priest and Victim, acts in His capacity as Head of the Church, He offers and immolates not only Himself, but all Christians, and in a certain manner, all of mankind.
The Treasures of the Eucharistic Sacrifice
Now if this holds true for all Christians, much more does it hold for priests, who are the ministers of Christ, principally in order to celebrate the Eucharistic Sacrifice. And precisely in the Eucharistic Sacrifice, when "in the person of Christ", he consecrates bread and wine, which become the Body and Blood of Christ, the priest can draw from that same fountain of the supernatural life the inexhaustible treasures of salvation and all those helps which he needs for himself personally and for the fulfillment of his mission.
Living the Mass
Being in such close contact with the divine mysteries, the priest cannot but be hungry and thirsty after justice, or not feel inspired to assimilate his life to his exalted dignity, and orient his life towards that sacrifice in which he must needs offer and immolate himself with Christ. Consequently, he will not merely celebrate Holy Mass, but will live it out intimately in his daily life; in no other way can he obtain that supernatural vigor which will transform him and make him a sharer in the life of sacrifice of the Redeemer.
Being a Victim with Jesus
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.
NECESSITY OF PRAYER AND PIETY
The Obligation of the Divine Office
Perfect sanctity also demands a continual communication with God; and because this intimate contact which the priestly soul should enjoy with God, ought never be interrupted in the succession of days and hours, the Church obliges the priest to recite the Divine Office. In this manner, she has been faithfully obedient to the injunction of the Lord, "That they must always pray and not lose heart".
Just as the Church herself never ceases praying, so she ardently desires that her children should do the same, repeating the words of the Apostle, "Through Him (Jesus), therefore, let us offer up a sacrifice of praise always to God, that is, fruit of lips praising His name".To priests, she has committed the special duty of consecrating to God, praying also in the name of the people, every period of the day and every circumstance of life."
"PART II. THE HOLINESS OF THE SACRED MINISTRY
The Redeemer's Side was pierced on Mount Calvary and from it flowed His Precious Blood running like a torrent in flood through the centuries to cleanse men's consciences, expiate their sins, impart to them the treasures of salvation.
The Priest as Dispenser of the Mysteries of God
It is the priests who are destined to carry out this mystery so sublime. Not only do they procure and communicate Christ's grace to the members of His Mystical Body, but they are also the organs whereby this Mystical Body develops because they must ever give the Church new sons, bring them up, educate them, and guide them. Priests are "the stewards of the mysteries of God"; therefore they must serve Jesus Christ with perfect charity and consecrate all their strength to the salvation of their brethren. They are the apostles of light; therefore they must illuminate the world with the teachings of the Gospel and be so strong in the Christian faith as to be able to communicate it to others, and follow the example and doctrine of the Divine Master in order to lead everyone to Him. They are the apostles of grace and pardon: therefore they must consecrate themselves entirely to the salvation of men and draw them to the altar of God in order that they may nourish themselves with the bread of eternal life. They are the apostles of charity: therefore they must promote works of charity, all the more urgent today when the needs of the indigent have grown enormously.
The priest must also strive to see that the faithful have a correct understanding of the doctrine of the "Communion of Saints," and that they feel and live it. For this purpose let him zealously recommend those institutions known as the Liturgical Apostolate and the Apostleship of Prayer. In like manner, he must promote all those forms of the apostolate which today, on account of the special needs of the Christian people, are so very important and urgent. Let him, therefore, labor most diligently for the diffusion of instruction in the Catechism, the development and diffusion of Catholic Action and Missionary Action, and, with the assistance of well prepared and trained laymen, let him increase those projects of the social apostolate which are demanded by our time.
Union With Christ in Apostolic Work
But the priest must remember that the closer he is united to Christ and guided in his activities by the spirit of Christ, the more fruitful his ministry will be. Thus, his priestly work will not be reduced to a purely natural activity which tires the body and mind and draws the priest himself away from the right path with no little detriment both to himself and to the Church. But his work and his labor will be fruitful and corroborated by those gifts of grace that God denies to the proud but concedes generously to those working humbly in "the Vineyard of the Lord," not seeking themselves and their own interestsbut the glory of God and the salvation of souls. Hence, faithful to the teachings of the Gospel, let him not trust in himself, as we have said, and in his own strength but let him place his faith in the help of the Lord. "So then neither he who plants is anything, nor he who waters, but God Who gives the growth".
When the apostolate is directed and inspired in this manner, it is impossible that the priest should not attract the souls of everyone to himself with an almost divine strength. By his reproducing in his habits and his life a living image of Christ, all those who turn to him as a master will recognize, thanks to some inward conviction, that words he speaks are not his but God's and that he does not act of his own accord but by the virtue of God: "If anyone speaks, let it be as with words of God. If anyone ministers, let it be as from the strength that God furnishes..." In striving towards holiness and in exercising his ministry with the greatest diligence, the priest must spend himself to represent Christ so perfectly as, in all modesty, to be able to repeat the words of the Apostle of the Gentiles, "Be imitators of me, as I am of Christ".
The Heresy Of Action
For these reasons, while giving due praise to those who in the years which have followed the long and terrible war, urged by the love of God and of doing good to their neighbor under the guidance and following the example of their Bishops, have consecrated their entire strength to the relief of so much misery, We cannot abstain from expressing our pre-occupation and our anxiety for those who on account of the special circumstances of the moment have become so engulfed in the vortex of external activity that they neglect the chief duty of the priest, his own sanctification. We have already stated publicly in writing that those who presume that the world can be saved by what has been rightly called "the heresy of action" must be made to exercise better judgment. The heresy of action is that activity which is not based upon the help of grace and does not make constant use of the means necessary to the pursuit of sanctity given us by Christ. In the same way, nevertheless, We have deemed it timely to stimulate to the activities of the ministry those who, shut up in themselves and almost diffident of the efficacy of divine aid, do not labor to the best of their ability to make the spirit of Christianity penetrate daily life in all those ways demanded by our times.
Complete Consecration to the Salvation of Souls
We earnestly exhort you, therefore, to labor with all solicitude for the salvation of those whom Providence has entrusted to your care, closely united to the Redeemer with whose strength we can do all things. How ardently We desire, O beloved sons, that you emulate those saints who in past times, by their great deeds, have shown what the might of Divine Grace can do in this world. May you one and all, in humility and sincerity, always be able to attribute to yourselves -- with your spiritual charges as witnesses -- the words of the Apostle, "But I will most gladly for my part, spend and be spent myself for your souls".Enlighten the minds, guide the consciences, comfort and sustain the souls who are struggling with doubt and groaning with sorrow. To these forms of apostolate, add also all those others which the needs of the times demand. But let it always be clear to everybody that the priest in all his activities seeks nothing beyond the good of souls, and looks toward no one but Christ to Whom he consecrates his energies and his whole self.
Following the Example of the Redeemer
In the same way that, in order to urge you to personal sanctification, We have exhorted you to reproduce in yourselves the living image of Christ, so now for the sanctifying efficacy of your ministry We excite you to follow constantly the example of the Divine Redeemer. Full of the Holy Ghost, He "went about doing good and healing all who were in the power of the devil; for God was with Him". Strengthened by the same Spirit and encouraged by His Strength, you will be able to exercise a ministry which, nourished and enkindled by Christian charity, will be rich in Divine virtue and capable of communicating this virtue to others. May your apostolic zeal be animated by that divine charity which bears everything with peace of mind, which does not let itself be overcome by adversity, and which embraces all, rich and poor, friends and enemies, faithful and unfaithful. This daily effort and these daily hardships are demanded of you by souls for whose salvation Our Saviour patiently suffered grief and torment unto death in order to restore us to the Divine Friendship. This is, and well you know it, the greatest good of all. Do not allow yourselves, therefore, to be carried away by the immoderate desire for success, do not allow yourselves to be dismayed if, after assiduous labor, you do not gather the desired fruits. "One sows, another reaps".
Charity in Apostolic Work
Furthermore, let your apostolic zeal shine with benign charity. If it be necessary -- and it is everyone's duty -- to fight error and repel vice, the soul of the priest must be ever open to compassion. Error must be fought with all our might, but the brother who errs must be loved intensely and brought to salvation. How much good have the saints not done, how many admirable deeds have they not performed by their kindness even in circumstances and in environments penetrated by lies and degraded by vice? Of a truth, he who to please men would gloss over their evil inclinations or be indulgent about their incorrect ways of thinking or acting, thereby prejudicing Christian teaching and integrity of morals, would be betraying his ministry. But when the teachings of the Gospel are preserved and those who stray are moved by the sincere desire to return to the right path, the priest must remember the reply of Our Lord to St. Peter when he asks Him how many times he must forgive his neighbor. "I do not say to thee seven times, but seventy times seven".
The object of your zeal must not be earthly and transient things but things eternal. The resolution of priests aspiring to holiness must be this: to labor solely for the glory of God and the salvation of souls. How many priests, even in the straitened circumstances of our time, have taken the example and the warnings of the Apostle of the Gentiles as a rule of conduct! The Apostle of the Gentiles, content with the indispensable minimum, declared: ". . . but having food and sufficient clothing, with these let us be content".
Increasing Knowledge and Zeal
Finally, this industrious zeal must be illuminated by the light of wisdom and discipline and inflamed by the fire of charity. Whoever sets before himself his own sanctification and that of other people must be equipped with solid learning that comprises not only theology but also the results of modern science and discovery so that, like a good father, he may draw "from his storeroom things new and old"and make his ministry always more appreciated and fruitful. In the first place, let your activities be inspired by and remain faithful to the prescriptions of this Apostolic See and the directives of the Bishops. May it never happen, beloved sons, that those new forms and methods of the apostolate, so opportune today especially in regions where the clergy is not sufficiently numerous, remain dead or, through poor direction, not correspond to the needs of the faithful.
May your zeal increase every day, therefore, sustain the Church of God, be an example to the faithful, and constitute a powerful bulwark against which the assaults of the enemies of God may be broken."
"Their Directors Must Instill in Them the Ecclesiastical Virtues
Those who are responsible for the moral training of seminarians must always aim at making them acquire all the virtues the Church demands in priests. Of these virtues We have already spoken in another part of this Exhortation and, therefore, there is no reason to return to the subject here. But We cannot refrain from indicating and recommending among all virtues that aspirants to the priesthood must firmly possess those upon which the moral structure of the priest is built, as upon solid pillars. Particularly Obedience
It is necessary that young men acquire the spirit of obedience by accustoming themselves to submit their own will sincerely to that of God manifested through the legitimate authority of the superiors. Nothing can be lamented more in the conduct of the future priest than that it is not in conformity with the Will of God. This obedience must always be inspired by the perfect model, the Divine Teacher Who on earth had but one single program "to do thy will, O God".
From the seminary on, the future priest must learn to give filial and sincere obedience to his superiors in order to be always ready later on to obey his Bishop docilely according to the teaching of the invincible Athlete of Christ, Ignatius of Antioch: "Obey ye all the bishop as Jesus Christ obeyed the Father". "He who honors the bishop is honored by God". "He who does anything without the Bishop's knowledge, serves the devil". "Do nothing without the bishop, keep your body like the temple of God, love union, flee discord, be an imitator of Jesus Christ as He was an imitator of His Father".
Solid and Proved Chastity
Every care and solicitude must be used to have the young soldiers of the sacred army appreciate, love, and preserve chastity, because the choice of the priestly state and perseverance in it depend in great part on this virtue. Being exposed to greater dangers, chastity must be solidly possessed and proved at length. Let seminarians, therefore, inform themselves about the nature of ecclesiastical celibacy, of the chastity that they must observe and of the obligations it brings with it, and let them be warned of the dangers they may meet. Let them take heed to defend themselves against these dangers from a tender age, having recourse faithfully to the means offered by Christian asceticism for bridling the passions, because the more strongly and efficaciously they control them, the further the soul will progress in the other virtues and the surer will be the fruit of their priestly ministry. Hence, whenever young seminarians show evil tendencies in this regard and, after a due trial, show themselves incorrigible, it is absolutely necessary to dismiss them from the seminary before they receive Holy Orders.
Devotion to the Blessed Sacrament
These and all the other priestly virtues can be easily acquired and firmly possessed by seminarians if from the beginning they have acquired and cultivated a sincere and tender devotion to Christ Jesus present "truly, really, and substantially" in our midst in the most august Sacrament, and if they make of Him the inspiration and the end of all their actions and their aspirations. And, if to devotion to the Blessed Sacrament they unite filial devotion to the Most Blessed Virgin Mary, full of trust and abandonment to the Mother of God and urging the soul to imitate her virtues, then the Church will be supremely happy, because the fruit of an ardent and zealous ministry can never be wanting in a priest whose adolescence has been nourished with the love of Jesus and Mary."