In Appendix VII, "Sacrifice and Priesthood in the Catholic Church" of his book, The Order of Melchisedech: A Defence of Catholic Priesthood (2d ed.; Kansas City, Miss.: Angelus Press, 1993), Michael Davies (1936-2004) offered the following evidence for a ministerial priesthood in early Christianity:
The Priesthood in the Early Church
The nascent Church did not wish to give to her sacred ministers the name "priests," so as to avoid all misunderstanding. The old law of sacrifices having been abolished, a new economy of salvation had begun. It was not immediately desirable that the ministers of the new Law should be called "priests," still less "Levites," for those names were reserved for the priesthood of the old Testament. Outside Israel the word "priest" even had a pagan flavour. But the Church soon perceived the deep parallelism existing between the ministers of the two economies of salvation. In the second century we already come across the word sacerdos for the Christian priest, even summus sacerdos for the bishop, in the writings of Tertullian (160-after 220), who speaks of sacerdotalia munera, sacerdotale officium, being exercised in the Christian Church. Saint Cyprian (200/10-258; bishop in 248/9) knows the tripartite division of the ministers of the Church into bishops, presbuteroi, deacons; and to specify the first two categories he also uses the word sacerdos. To explain that, it seems unnecessary to have recourse to the parallelism Old Testament-----New Testament; in Latin, presbyter was still a foreign word, and sacerdos was not. But if, early on, the presbuteroi began to be called sacerdotes, that, even so, proves that the term was well suited to their function. In the Churches of the East the words hiereus, hierosune (priest, priesthood), etc., appear very early to designate the ministers of the New Testament, bishops and priests. In the Apostolic Constitutions, an apocryphal work of Syrian origin (c. 380), we read that, as Moses had instituted a high priest, priests and Levites, the Lord instituted in His Church Apostles-----James, Clement and others----- who all instituted "presbyters," deacons, subdeacons and rectors. The analogy with the priesthood of the Old Testament is clearly expressed (VIII:46,13). The author continues with an even clearer expression: "He who by His nature is the first pontiff (archiereus), Christ, the only Son, did not snatch the honour for Himself but was instituted by the Father; becoming man for our sake and offering to God His Father the spiritual sacrifice (thusian) before the Passion, He commanded only us to do that, though there are other men with us who have received the faith, but it goes without saying that it is not because a man has received the faith that he has already been instituted priest (hiereus) or has received the dignity of pontiff (archieratikes axias). After His Ascension, we ourselves (i.e. the Apostles), offering according to His command a pure and unbloody sacrifice, chose bishops and presbyters and seven deacons" (VIII:46, 14-15). A little further on the author tells his readers that Stephen, the first deacon, was never seen to do what did not belong to his ministry as deacon, "offering the sacrifice or laying hands on any one" (VIII: 46, 16).
There already is the whole doctrine of the priesthood of the ministers of the Christian cult, just as it will later be proposed, repeated rather, by the Council of Trent. The ministerial priesthood is there connected with that of Christ and there is an unbloody sacrifice which only priests can offer. Although the Apostolic Constitutions were written in the 4th century, probably in Syria, the author presents their doctrine as already old, as coming from the Apostles. He could not have done that had it been a complete innovation. It is true that the synod "in Trullo" (the Quinisextum, 692, not received by Rome) rejected the Apostolic Constitutions as "falsified by the heretics" (the author was Arian), but still it did make chapter 47 of book VIII its own, the so-called "Apostolic Canons" of which the second speaks of the sacrifice (thusia) which the bishop or the presbyters offer "on the altar of God."
Two eastern Fathers well known for their writings on the priesthood are Saint Gregory Nazianzen and Saint John Chrysostom. The first (320/30-390) was ordained priest by his father, bishop of Nazianzus in Cappadocia (Asia Minor), against his will. Yielding at first to the entreaties of the community, he soon withdrew from his new ministry by flight. To justify that, he wrote his "Apologia for my flight to Pontus," in which he set out the duties of the priest, especially his pastoral duties. In this exposition, the first of its kind in the East, bishop and priest are often given the name hiereus. Much better known is the celebrated work of Saint John Chrysostom (344/54- 407), Peri Hierosunes, "On the Priesthood," in six books, written about 396. The work is pastoral and has had an enormous success down to the present day. For Saint John, the hiereus, the priest tout court, is the bishop. In Book III, chapter 4, there is a sublime passage which treats of his sacerdotal ministry. "Although the priesthood," he says, "is exercised on earth, its place is with the heavenly institutions. It is the Holy Ghost Who established it and Who wished that men of flesh should exercise the ministry of Angels. The priest therefore should be as pure as if he dwelt in Heaven with the Angelic powers. In the Old Testament, the adornments of the high priest struck fear into the Israelites; but we must say with the Apostle: "What, in that, was glorious is glorious no longer, because of the glory which excels" (2 Cor. 3:10); and the author continues: "When you see the Lord lying immolated (tethumenon), and the priest standing before the sacrifice (toi thumati) and praying, and all become red with this Precious Blood, do you think you are still on earth among men? Do you not, rather, feel lifted up to Heaven? . . . O admirable vision! o love of God for man! He Who is enthroned in the heights with the Father is at this moment touched by the hands of all!" "At the sacrifice of Elias on Mount Carmel"-----it is still Saint John Chrysostom-----"fire fell upon the holy sacrifice. With us, the priest brings down not fire but the Holy Ghost; grace comes down upon the sacrifice and sets on fire the souls of all. It is a terrible mystery; no human soul could endure that flame of the sacrifice if God did not help with His powerful grace."
A third author, this time from the West, who has treated at length of the ministry of the pastors of the Church is Saint Gregory the Great (540-604; Pope 590-604), in his Regula Pastoralis written in 590 when he was elected Peter's successor. It is addressed to the bishop of Ravenna. Like the two preceding works, this also is pastoral in character; the holy Pope is setting out his own programme as Pastor of the Church.
The meaning of the texts quoted is clear; but others are sometimes less so. When the Fathers and the old ecclesiastical writers speak of the Christian priesthood and sacrifice, one must always be careful to ask in what sense they use those words-----in the literal, or in a metaphorical and "spiritual" sense. Great circumspection is required when it is a question of finding Catholic doctrine with certainty. That is why some hesitate to quote in this context the famous text of the Didache, chapter 14 (which seems clear enough, but which is short), where the celebration of the Eucharist is called a sacrifice (thusia) by which the famous prophecy of Malachy (1:11) is fulfilled. Reluctance to interpret such a text has its roots in the Old Testament. After the exile there was an increasingly marked tendency in the people of Israel to give to prayer, above all the prayer of praise, a value equal to or even greater than ritual sacrifices. The great majority of the Jews, many of whom lived in exile, in the Diaspora, could assist at the temple sacrifices only rarely in their lives, or perhaps never. But the more pious had the custom of praying several times a day, turned towards the temple; and for them that sufficed: for them prayer took the place of sacrifice.
Saint Paul speaks of "the sacrifice (thusia) and the liturgy of our faith" (Phil. 2:17): that is faith itself, living in works. The material gifts of the Church of Philippi which Epaphroditus had just brought to the apostle in prison are called "an odour of sweetness (a sacrificial term, cf. Exod. 29:18, 41), a sacrifice (thusian) which God receives and finds acceptable" (Phil. 4:18). The apostle writes to the Romans: "I beseech you therefore, brethren . . . to offer your persons a living sacrifice (thusian zosan), holy, pleasing to God; that is your spiritual worship" (ten logiken latreian humon) (Rom. 12:1). To the Hebrews: "By Him (by Christ) we offer to God a sacrifice of praise (thusian aineseos), that is to say, the fruit of lips confessing His name. As to deeds of kindness and the sharing of goods . . . it is in such sacrifices (thusiais) that God takes pleasure" (Heb. 13:15-16). The First Epistle of Saint Peter exhorts the Christians, called "a chosen generation, a kingly priesthood, a holy nation, a purchased people" (1 Peter 2:9) "to offer up spiritual sacrifices (pneumatikis thusias) acceptable to God by Jesus Christ" (1 Peter 2:5); according to the author the whole of the Christian life should be a worship pleasing to God.
In the light of these texts from Holy Scripture there is clearly a difficulty in deciding the exact meaning of chapter 14 of the Didache and of certain other words of writers of Christian antiquity. The unexpected novelty of the new economy of salvation was not expressed at once in perfectly clear and unambiguous language-----which should surprise no one. Under the guidance of the Holy Spirit the Church became more and more aware of the whole content of the revealed truth entrusted to her by her Lord and God. As regards the Christian priesthood, this awareness was achieved very quickly, in a concordant and harmonious way. The texts quoted from the Apostolic Constitutions and from Saint John Chrysostom are proof of that. Is more required? The sacrificial character of the Eucharistic celebration is nowhere more vigorously affirmed and emphasized than in the old liturgy of the Nestorian Church which prefers to be called "The Church of the East" tout court. That affirmation is repeated throughout the ceremony. When the anaphora begins, the priest, instead of saying "Let us give thanks to the Lord," as in the other liturgies, sings aloud: "A sacrifice is offered to Almighty God." An anonymous commentator on this liturgy, writing in the 11th century, does not want more than one priest to celebrate ("concelebrare") at the altar, because there the priest is taking the place of Christ Who is the only High Priest of the New Testament. The Eucharistic liturgy is called not only qurbana, a word which could be translated strictly by "offering," but also debheta, a word which means a bloody sacrifice and which carries us back to the sacrifice of Our
Lord on the Cross. The witness of the "Church of the East" is of special importance because that Church very early declared itself independent of the others (in 424, under Persian influence) and developed after that in isolation. If the doctrine of the sacrificial character of the Eucharist is there so plainly asserted, it is because there we have an authentic Christian doctrine contained in the deposit of revelation.
For more on the biblical and historical evidence for an ordained, ministerial priesthood in the New Covenant, see my book, After the Order of the Son of God: The Biblical and Historical Evidence for Latter-day Saint Theology of the Priesthood