I thought this brief excerpt from Philip Schaff might shed some light on the subject.
From History of the Christian Church by Philip Schaff:
J.B. Lightfoot begins his valuable discussion on the Christian ministry with this broad and liberal statement: "The kingdom of Christ, not being a kingdom of this world, is not limited by the restrictions which fetter other societies, political or religious. It is in the fullest sense free, comprehensive, universal. It displays this character, not only in the acceptance of all comers who seek admission, irrespective of race or caste or sex, but also in the instruction and treatment of those who are already its members. It has no sacred days or seasons, no special sanctuaries, because every time and every place alike are holy. Above all it has no sacerdotal system. It interposes no sacrificial tribe or class between God and man, by whose intervention alone God is reconciled and man forgiven. Each individual member holds personal communion with the Divine Head. To Him immediately he is responsible, and from Him directly he obtains pardon and draws strength."
While we must deny a divine right and perpetual obligation to any peculiar form of government as far as it departs from the simple principles of the New Testament...the most that can be said is, that the apostolic age contains fruitful germs for various ecclesiastical organizations subsequently developed, but none of them can claim divine authority except for the gospel ministry, which is common to all. Dean Stanley asserts that no existing church can find any pattern or platform of its government in the first century, and thus strongly contrasts the apostolic and post-apostolic organizations (l.c.): "It is certain that the officers of the apostolical or of any subsequent church, were not part of the original institution of the Founder of our religion; that of Bishop, Presbyter, and Deacon; of Metropolitan, Patriarch, and Pope, there is not the shadow of a trace in the four Gospels. It is certain that they arose gradually out of the preexisting institutions either of the Jewish synagogue, or of the Roman empire, or of the Greek municipalities, or under the pressure of local emergencies. It is certain that throughout the first century, and for the first years of the second, that is, through the later chapters of the Acts, the Apostolical Epistles, and the writings of Clement and Hermas. Bishop and Presbyter were convertible terms, and that the body of men so-called were the rulers-so far as any permanent rulers existed-of the early church. It is certain that, as the necessities of the time demanded, first at Jerusalem, then in Asia Minor, the elevation of one Presbyter above the rest by the almost universal law, which even in republics engenders a monarchial element, the word ’Bishop’ gradually changed its meaning, and by the middle of the second century became restricted to the chief Presbyter of the locality.Bishop Lightfoot states, "The episcopate (Bishoprick or Pastorate) was formed,not out of the apostolic order by localization, but out of the presbyterial by elevation; and the title, which originally was common to all, came at length to be appropriated to the chief among them."
It is certain that in no instance were the apostles called ’Bishops’ in any other sense than they were equally called ’Presbyters’ and ’Deacons.’ It is certain that in no instance before the beginning of the third century the title or function of the Pagan or Jewish priesthood is applied to the Christian pastors .... It is as sure that nothing like modern Episcopacy existed before the close of the first century as it is that nothing like modern Presbyterianism existed after the beginning of the second. That which was once the Gordian knot of theologians has at least in this instance been untied, not by the sword of persecution, but by the patient unravelment of scholarships."
The idea and institution of a special priesthood, distinct from the body of the people, with the accompanying notion of sacrifice and altar, passed imperceptibly from Jewish and heathen reminiscences and analogies into the Christian church. The majority of Jewish converts adhered tenaciously to the Mosaic institutions and rites, and a considerable part never fully attained to the height of spiritual freedom proclaimed by Paul, or soon fell away from it. He opposed legalistic and ceremonial tendencies in Galatia and Corinth; and although sacerdotalism does not appear among the errors of his Judaizing opponents, the Levitical priesthood, with its three ranks of high-priest, priest, and Levite, naturally furnished an analogy for the threefold ministry of bishop, priest, and deacon, and came to be regarded as typical of it. Still less could the Gentile Christians, as a body, at once emancipate themselves from their traditional notions of priesthood, altar,and sacrifice, on which their former religion was based. Whether we regard the change as an apostasy from a higher position attained, or as a reaction of old ideas never fully abandoned, the change is undeniable, and can be traced to the second century. The church could not long occupy the ideal height of the apostolic age, and as the Pentecostal illumination passed away with the death of the apostles, the old reminiscences began to reassert themselves.
In the apostolic church preaching and teaching were not confined to a particular class, but every convert could proclaim the gospel to unbelievers, and every Christian who had the gift could pray and teach and exhort in the congregation. Compare Acts 8:4; 9:27; 13:15; 18:26, 28; Rom. 12:6; 1 Cor. 12:10, 28; 14:1-6, 31. Even in the Jewish Synagogue the liberty of teaching was enjoyed, and the elder could ask any member of repute, even a stranger, to deliver a discourse on the Scripture lesson (Luke 4:17; Acts 17:2). The New Testament knows no spiritual aristocracy or nobility, but calls all believers "saints" though many fell far short of their vocation. Nor does it recognize a special priesthood in distinction from the people, as mediating between God and the laity. It knows only one high-priest, Jesus Christ, and clearly teaches the universal priesthood, as well as universal kingship, of believers.1 Pet. 2:5, 9; 5:3; Rev. 1:6; 5:10; 20:6. Neander,
Lightfoot, Stanley, agree. I add a passage from Hatch’s; Bampton Lectures on The Organization of the Early Christian Churches (1881), p. 139: "In earlier times there was a grander faith. For the kingdom of God was a kingdom of priests. Not only the ’four and twenty elders’ before the throne, but the innumerable souls of the sanctified upon whom ’the second death had no power,’ were ’kings and priests unto God.’ Only in that high sense was priesthood predicable of Christian men. For the shadow had passed: the reality had come: the one High Priest of Christianity was Christ." It does this in a far deeper and larger sense than the Old; in a sense, too, which even to this day is not yet fully realized. The entire body of Christians are called "clergy" (klh'roi a peculiar people, the heritage of God.
On the other hand it is equally clear that there was in the apostolic church a ministerial office, instituted by Christ, for the very purpose of raising the mass of believers from infancy and pupilage to independent and immediate intercourse with God, to that prophetic, priestly, and kingly position, which in principle and destination belongs to them all. This work is the gradual process of church history itself, and will not be fully accomplished till the kingdom of glory shall come. But these ministers are nowhere represented as priests in any other sense than Christians generally are priests, with the privilege of a direct access to the throne of grace in the name of their one and eternal high-priest in heaven. Even in the Pastoral Epistles which present the most advanced stage of ecclesiastical organization in the apostolic period, while the teaching, ruling, and pastoral functions of the presbyter-bishops are fully discussed, nothing is said about a sacerdotal function. The Apocalypse, which was written still later, emphatically teaches the universal priesthood and kingship of believers. The apostles themselves never claim or exercise a special priesthood. The sacrifice which all Christians are exhorted to offer is the sacrifice of their person and property to the Lord, and the spiritual sacrifice of thanksgiving and praise. In one passage a Christian "altar" is spoken of, in distinction from the Jewish altar of literal and daily sacrifices, but this altar is the cross on which Christ offered himself once and forever for the sins of the world.
After the gradual abatement of the extraordinary spiritual elevation of the apostolic age, which anticipated in its way the ideal condition of the church, the distinction of a regular class of teachers from the laity became more fixed and prominent. This appears first in Ignatius, who, in his high episcopalian spirit, considers the clergy the necessary medium of access for the people to God. "Whoever is within the sanctuary (or altar), is pure; but he who is outside of the sanctuary is not pure; that is, he who does anything without bishop and presbytery and deacon, is not pure in conscience." Yet he nowhere represents the ministry as a sacerdotal office. The Didache calls "the prophets" high-priests, but probably in a spiritual sense. Clement of Rome, in writing to the congregation at Corinth, draws a significant and fruitful parallel between the Christian presiding office and the Levitical priesthood, and uses the expression "layman" as antithetic to high-priest, priests, and Levites. This parallel contains the germ of the whole system of sacerdotalism. But it is at best only an argument by analogy. Tertullian was the first who expressly and directly asserts sacerdotal claims on behalf of the Christian ministry, and calls it "sacerdotium," although he also strongly affirms the universal priesthood of all believers. Cyprian (d. 258) goes still further, and applies all the privileges, duties, and responsibilities of the Aaronic priesthood to the officers of the Christian church, and constantly calls them sacerdotes and sacerdotium. He may therefore be called the proper father of the sacerdotal conception of the Christian ministry as a mediating agency between God and the people. During the third century it became customary to apply the term "priest" directly and exclusively to the Christian ministers especially the bishops. Bishop Lightfoot states, "The episcopate
(Bishoprick or Pastorate) was formed, not out of the apostolic order by localization, but out of the presbyterial by elevation; and the title, which originally was common to all, came at length to be appropriated to the chief among them."
In the same manner the whole ministry, and it alone, was called "clergy," with a double reference to its presidency and its peculiar relation to God. It was distinguished by this name from the Christian people or "laity." Thus the term "clergy," which first signified the lot by which office was assigned (Acts 1:17, 25), then the office itself, then the persons holding that office, was transferred from the Christians generally to the ministers exclusively.
Solemn "ordination" or consecration by the laying on of hands was the form of admission into the "ordo ecclesiasticus" or "sacerdotalis." In this order itself there were again three degrees, "ordines majores," as they were called: the diaconate, the presbyterate, and the episcopate-held to be of divine institution. Under these were the "ordines minores," of later date, from sub-deacon to ostiary, which formed the stepping-stone between the clergy proper and the people.
Thus we find, so early as the third century, the foundations of a complete hierarchy; though a hierarchy of only moral power, and holding no sort of outward control over the conscience. The body of the laity consisted of two classes: the faithful, or the baptized and communicating members, and the catechumens, who were preparing for baptism. Those church members who lived together in one place, formed a church in the narrower sense.
With the exaltation of the clergy appeared the tendency to separate them from secular business, and even from social relations-from marriage, for example-and to represent them, even outwardly, as a caste independent of the people, and devoted exclusively to the service of the sanctuary. They drew their support from the church treasury, which was supplied by voluntary contributions and weekly collections on the Lord’s Day. After the third century they were forbidden to engage in any secular business, or even to accept any trusteeship. Celibacy was not yet in this period enforced, but left optional. Tertullian, Gregory of Nyssa, and other distinguished church teachers, lived in wedlock, though theoretically preferring the unmarried state. Of an official clerical costume no certain trace appears before the fourth century; and if it came earlier into use, as may have been the case, after the example of the Jewish church, it must have been confined, during the times of persecution, to the actual exercises of worship.
With the growth of this distinction of clergy and laity, however, the idea of the universal priesthood continued from time to time to assert itself: in Irenaeus, for example, and in an eccentric form in the Montanists, who even allowed women to teach publicly in the church. So Tertullian, with whom clerus and laici were at one time familiar expressions, inquires, as the champion of the Montanistic reaction against the Catholic hierarchy: "Are not we laymen priests also?" It is written, he continues: "He hath made us kings and priests (Rev. 1:6). It is the authority of the church alone which has made a distinction between clergy and laity. Where there is no college of ministers, you administer the sacrament, you baptize, you are a priest for yourself alone. And where there are three of you, there is a church, though you be only laymen. For each one lives by his own faith, and there is no respect of persons with God." All, therefore, which the clergy considered peculiar to them, he claimed for the laity as the common sacerdotal privilege of all Christians.
The clergy, according to the precedent of the Old Testament, came to be more and more rigidly distinguished, as a peculiar order, from the body of the laity. The ordination, which was solemnized by the laying on of hands and prayer, with the addition at a later period of an anointing with oil and balsam, marked the formal entrance into the special priesthood, as baptism initiated into the universal priesthood; and, like baptism, it bore an indefeasible character (character indelebilis). By degrees the priestly office assumed the additional distinction of celibacy and of external marks, such as tonsure, and sacerdotal vestments worn at first only during official service, then in every-day life. The idea of the universal priesthood of believers retreated in proportion, though it never passed entirely out of sight, but was from time to time asserted even in this age. Augustine, for example, says, that as all are called Christians on account of their
baptism, so all believers are priests, because they are members of the one High Priest.The progress of the hierarchical principle also encroached gradually upon the rights of the people in the election of their pastors. But in this period it did not as yet entirely suppress them. The lower clergy were chosen by the bishops, the bishops by their colleagues in the province and by the clergy.
