By virtue of our Baptism and our Confirmation we are priests, members of the one priesthood of Jesus Christ. Of course this does not make all of us ministerial priests, only those who are consecrated and ordained. On all this the Catechism is quite clear and concise. Beyond that this passage also so demonstrates the scriptural basis of the Church's understanding of the priesthood of the new and everlasting covenant.
1539 The chosen people was constituted by God as "a kingdom of priests and a holy nation" (Ex 19,6;Isa 61,6). But within the people of Israel, God chose one of the twelve tribes, that of Levi, and set it apart for liturgical service; God himself is its inheritance Num 1,48-53; Jos 31,3) A special rite consecrated the beginnings of the priesthood of the Old Covenant. the priests are "appointed to act on behalf of men in relation to God, to offer gifts and sacrifices for sins" (Lev 8; Ex 29,1-30).
1540 Instituted to proclaim the Word of God and to restore communion with God by sacrifices and prayer, (Mal 2,7-9) this priesthood nevertheless remains powerless to bring about salvation, needing to repeat its sacrifices ceaselessly and being unable to achieve a definitive sanctification, which only the sacrifice of Christ would accomplish (Heb 5,3; Heb 7,27).
1541 The liturgy of the Church, however, sees in the priesthood of Aaron and the service of the Levites, as in the institution of the seventy elders, (Num 11,24-25) a prefiguring of the ordained ministry of the New Covenant. Thus in the Latin Rite the Church prays in the consecratory preface of the ordination of bishops:
by your gracious word
you have established the plan of your Church.
From the beginning,
you chose the descendants of Abraham to be your holy nation.
You established rulers and priests
and did not leave your sanctuary without ministers to serve you....
1542 At the ordination of priests, the Church prays:
when you had appointed high priests to rule your people,
you chose other men next to them in rank and dignity
to be with them and to help them in their task....
you extended the spirit of Moses to seventy wise men....
You shared among the sons of Aaron
the fullness of their father's power . . .
As ministers of your tabernacle you chose the sons of Levi
and gave them your blessing as their everlasting inheritance.
The one priesthood of Christ.
1544 Everything that the priesthood of the Old Covenant prefigured finds its fulfillment in Christ Jesus, the "one mediator between God and men" 2 Tim 2,5) The Christian tradition considers Melchizedek, "priest of God Most High," as a prefiguration of the priesthood of Christ, the unique "high priest after the order of Melchizedek"; (Heb 5,10; Heb 6,20; Gen 14,18) "holy, blameless, unstained, (Heb 7,26) "by a single offering he has perfected for all time those who are sanctified," (Heb 10,14) that is, by the unique sacrifice of the cross.
1545 The redemptive sacrifice of Christ is unique, accomplished once for all; yet it is made present in the Eucharistic sacrifice of the Church. the same is true of the one priesthood of Christ; it is made present through the ministerial priesthood without diminishing the uniqueness of Christ's priesthood: "Only Christ is the true priest, the others being only his ministers" (Heb 8,4).
Two participations in the one priesthood of Christ
1546 Christ, high priest and unique mediator, has made of the Church "a kingdom, priests for his God and Father" (Rev 1,6; Rev 5,9-10; 1 Pet 2,5.9). The whole community of believers is, as such, priestly. the faithful exercise their baptismal priesthood through their participation, each according to his own vocation, in Christ's mission as priest, prophet, and king. Through the sacraments of Baptism and Confirmation the faithful are "consecrated to be . . . a holy priesthood" (Lumen Gentium, 10 #1).
1547 The ministerial or hierarchical priesthood of bishops and priests, and the common priesthood of all the faithful participate, "each in its own proper way, in the one priesthood of Christ." While being "ordered one to another," they differ essentially (Lumen Gentium, 10 #2). In what sense? While the common priesthood of the faithful is exercised by the unfolding of baptismal grace - a life of faith, hope, and charity, a life according to the Spirit - ,the ministerial priesthood is at the service of the common priesthood. It is directed at the unfolding of the baptismal grace of all Christians. the ministerial priesthood is a means by which Christ unceasingly builds up and leads his Church. For this reason it is transmitted by its own sacrament, the sacrament of Holy Orders.
Why this long passage today? Because I have been fielding a lot of questions lately about the priesthood by Catholics who have been discussing our faith with members of the LDS Church. It is always more important to explain what we believe and why we believe it than to denigrate the beliefs of others, which they hold in good faith. St. Peter counseled the early Christians to always "be ready to give an explanation to anyone who asks you for a reason for your hope, but do it with gentleness and reverence, keeping your conscience clear, so that, when you are maligned, those who defame your good conduct in Christ may themselves be put to shame." St. Peter continues, recognizing that good deeds do not always go unpunished: "For it is better to suffer for doing good, if that be the will of God, than for doing evil" 1 Peter 3,15-17). Given that our celebration of the Mass of the Lord's Supper last Thursday, Holy Thursday, was a commemoration of the institution of the Eucharist, which is the source and summit of our faith, as well as the sacrifice offered by priests on behalf of and in cooperation with God's priestly people. This Mass also celebrates and commemorates the institution of the ministerial, or, ordained priesthood, it seems an opportune time to reflect on these matters. It is also good show how The Catechism of the the Catholic Church is the resource par excellance of learning, knowing, and explaining our faith. Along with its companion volume, The Compendium of the Catechism of the the Catholic Church, the Holy Bible, and The Catholic Book of Household Blessings it is a book that should be found in every Catholic home, bookmarked and dog-eared.
The first priests of the new covenant were the apostles, who, in turn, ordained priests and bishops as the faith grew and spread, which it did not really do until after St. Paul's conversion. The successors of the apostles are the college of bishops. Apostolic succession is a key feature of the priesthood, what Bishop Duane G. Hunt described as the "unbroken chain" going back to our Lord himself.
Alleluia! He is risen, indeed!