Christ the Lord, High Priest taken from among men, made the new people "a kingdom and priests to God the Father". The baptized, by regeneration and the anointing of the Holy Spirit, are consecrated as a spiritual house and a holy priesthood, in order that through all those works which are those of the Christian man they may offer spiritual sacrifices and proclaim the power of Him who has called them out of darkness into His marvelous light. Therefore all the disciples of Christ, persevering in prayer and praising God, should present themselves as a living sacrifice, holy and pleasing to God. Everywhere on earth they must bear witness to Christ and give an answer to those who seek an account of that hope of eternal life which is in them.
Through the ordination, some Christians are made holy stewards in the name of Christ and receive the gift of the Holy Spirit to feed the Church with the word and grace of God. Though they differ from one another in essence and not only in degree, the common priesthood of the faithful and the ministerial or hierarchical priesthood are nonetheless interrelated: each of them in its own special way is a participation in the one priesthood of Christ. The ministerial priest, by the sacred power he enjoys, teaches and rules the priestly people; acting in the person of Christ, he makes present the Eucharistic sacrifice, and offers it to God in the name of all the people. But the faithful, in virtue of their royal priesthood, join in the offering of the Eucharist. They likewise exercise that priesthood in receiving the sacraments, in prayer and thanksgiving, in the witness of a holy life, and by self-denial and active charity.
For the nurturing and constant growth of the People of God, Christ the Lord instituted in His Church a variety of ministries, which work for the good of the whole body. For those ministers, who are endowed with sacred power, serve their brethren, so that all who are of the People of God, and therefore enjoy a true Christian dignity, working toward a common goal freely and in an orderly way, may arrive at salvation. For "Christ, whom the Father has sanctified and sent into the world, has through His apostles, made their successors, the bishops, partakers of His consecration and His mission. They have legitimately handed on to different individuals in the Church various degrees of participation in this ministry. Thus the divinely established ecclesiastical ministry is exercised on different levels by those who from antiquity have been called bishops, priests and deacons.”
Bishops, vicars and ambassadors of Christ, by the Holy Spirit who was given them in ordination, have become true and authentic teachers of faith, priests and shepherds. They are called "prelates," heads of the people whom they govern. A bishop marked with the fullness of the sacrament of Orders, is "the steward of the grace of the supreme priesthood,” especially in the Eucharist, which he offers or causes to be offered, and by which the Church continually lives and grows. Bishops by praying and laboring for the people, make outpourings in many ways and in great abundance from the fullness of Christ's holiness. By the ministry of the word they communicate God's power to those who believe unto salvation and through the sacraments, the regular and fruitful distribution of which they regulate by their authority, they sanctify the faithful. They direct the conferring of baptism, by which a sharing in the kingly priesthood of Christ is granted. They are the original ministers of confirmation, dispensers of sacred Orders and the moderators of penitential discipline, and they earnestly exhort and instruct their people to carry out with faith and reverence their part in the liturgy and especially in the holy sacrifice of the Mass. And lastly, by the example of their way of life they must be an influence for good to those over whom they preside, refraining from all evil and, as far as they are able with God's help, exchanging evil for good, so that together with the flock committed to their care they may arrive at eternal life.
Priests, although they do not possess the highest degree of the priesthood, and although they are dependent on the bishops in the exercise of their power, nevertheless they are united with the bishops in sacerdotal dignity. By the power of the sacrament of Orders, in the image of Christ the eternal high Priest, they are consecrated to preach the Gospel and shepherd the faithful and to celebrate divine worship, so that they are true priests of the New Testament. Partakers of the function of Christ the sole Mediator, on their level of ministry, they announce the divine word to all. They exercise their sacred function especially in the Eucharistic worship or the celebration of the Mass by which acting in the person of Christ and proclaiming His Mystery they unite the prayers of the faithful with the sacrifice of their Head and renew and apply in the sacrifice of the Mass until the coming of the Lord the only sacrifice of the New Testament namely that of Christ offering Himself once for all a spotless Victim to the Father. For the sick and the sinners among the faithful, they exercise the ministry of alleviation and reconciliation and they present the needs and the prayers of the faithful to God the Father. Exercising within the limits of their authority the function of Christ as Shepherd and Head, they gather together God's family as a brotherhood all of one mind, and lead them in the Spirit, through Christ, to God the Father. In the midst of the flock they adore Him in spirit and in truth. Finally, they labor in word and doctrine, believing what they have read and meditated upon in the law of God, teaching what they have believed, and putting in practice in their own lives what they have taught.
At a lower level of the hierarchy are deacons, upon whom hands are imposed "not unto the priesthood, but unto a ministry of service.” For strengthened by sacramental grace, in communion with the bishop and his group of priests they serve in the diaconate of the liturgy, of the word, and of charity to the people of God. It is the duty of the deacon, according as it shall have been assigned to him by competent authority, to administer baptism solemnly, to be custodian and dispenser of the Eucharist, to assist at and bless marriages in the name of the Church, to bring Viaticum to the dying, to read the Sacred Scripture to the faithful, to instruct and exhort the people, to preside over the worship and prayer of the faithful, to administer sacramentals, to officiate at funeral and burial services. Dedicated to duties of charity and of administration, let deacons be mindful of the admonition of Blessed Polycarp: "Be merciful, diligent, walking according to the truth of the Lord, who became the servant of all.”
Holy Orders are given through the laying on of the Bishop's hands and prayer, in which the Bishop blesses God and pleads for the gift of the Holy Spirit to perform his ministry. In the light of tradition, especially witnessed by the liturgical rites and practice of the Church both in the East and in the West, it turns out that through the laying on of hands and the prayer of Holy Orders, the gift of the Holy Spirit and the sacred mark are given, so that bishops, priests and deacons become similar to Christ.