The assertion of the deity of the Son incarnate in Christ raised another problem which constituted the subject of dispute in the Christological controversies of the 4th and following centuries. What is the relation of the divine and human natures in Christ? At the council of Chalcedon in 451 it was declared that in the person of Christ are united two complete natures, divine and human, which retain after the union all their properties unchanged. This was supplemented at the third council of Constantinople in 680 by the statement that each of the natures contains a will, so that Christ possesses two wills. The Western Church accepted the decisions of Nicaea, Chalcedon and Constantinople, and so the doctrines of the Trinity and of the two natures in Christ were handed down as orthodox dogma in West as well as East.
Meanwhile in the Western Church the subject of sin and grace, and the relation of divine and human activity in salvation, received especial attention; and finally, at the second council of Orange in 529, after both Pelagianism and semi-Pelagianism had been repudiated, a moderate form of Augustinianism was adopted, involving the theory that every man as a result of the fall is in such a condition that he can take no steps in the direction of salvation until he has been renewed by the divine grace given in baptism, and that he cannot continue in the good thus begun except by the constant assistance of that grace, which is mediated only by the Catholic Church. This decision was confirmed by Pope Boniface II., and became the accepted doctrine in the Western Church of the middle ages. In the East, Augustine’s predestinationism had little influence, but East and West were one in their belief that human nature had been corrupted by the fall, and that salvation therefore is possible only to one who has received divine grace through the sacraments. Agreeing as they did in this fundamental theory, all differences were of minor concern.
In general it may be said that the traditional theology of the Church took its material from various sources—Hebrew, Christian, Oriental, Greek and Roman. The forms in which it found expression were principally those of Greek philosophy on the one hand and of Roman law on the other (see [Christianity]).
6. Organization.—The origin and early development of ecclesiastical organization are involved in obscurity. Owing to the once prevalent desire of the adherents of one or another polity to find support in primitive precept or practice, the question has assumed a prominence out of proportion to its real importance, and the few and scattered references in early Christian writings have been made the basis for various elaborate theories.
In the earliest days the Church was regarded as a divine institution, ruled not by men but by the Holy Spirit. At the same time it was believed that the Spirit imparted different gifts to different believers, and each gift fitted its recipient for the performance of some service, being intended not for his own good but for the good of his brethren (cf. 1 Cor. xii.; Eph. iv. 11). The chief of these was the gift of teaching, that is, of understanding and interpreting to others the will and truth of God. Those who were endowed more largely than their fellows with this gift were commonly known as apostles, prophets and teachers (cf. Acts xiii. 1; 1 Cor. xii. 28; Eph. ii. 20, iii. 5, iv. 11; Didachē, xi.). The apostles were travelling missionaries or evangelists. There were many of them in the primitive Church, and only gradually did the term come to be applied exclusively to the twelve and Paul. There is no sign that the apostles, whether the twelve or others, held any official position in the Church. That they had a large measure of authority of course goes without saying, but it depended always upon their brethren’s recognition of their possession of the divine gift of apostleship, and the right of Churches or individuals to test their claims and to refuse to listen to them if they did not vindicate their divine call was everywhere recognized. Witness, for instance, Paul’s reference to false apostles in 2 Cor. xi. 13, and his efforts to establish his own apostolic character to the satisfaction of the Corinthians and Galatians (1 Cor. ix. 1 ff.; 2 Cor. x. 13; Gal. i. 8 ff.); witness the reference in Rev. ii. 2 to the fact that the Church at Ephesus had tried certain men who claimed to be apostles and had found them false, and also the directions given in the Didachē for testing the character of those who travelled about as apostles. The passage in the Didachē is especially significant: “Concerning the apostles and prophets, so do ye according to the ordinance of the gospel. Let every apostle when he cometh to you be received as the Lord. But he shall not abide more than a single day, or if there be need a second likewise. But if he abide three days he is a false prophet. And when the apostle departeth let him receive nothing save bread until he findeth shelter. But if he ask money he is a false prophet” (ch. xi.). It is clear that a man who is to be treated in this way by the congregation is not an official ruler over it.
Between the apostles, prophets and teachers no hard-and-fast lines can be drawn. The apostles were commonly missionary prophets, called permanently or temporarily to the special work of evangelization (cf. Acts xiii. 1; Did. xi.), while the teachers seem to have been distinguished both from apostles and prophets by the fact that their spiritual endowment was less strikingly supernatural. The indefiniteness of the boundaries between the three classes, and the free interchange of names, show how far they were from being definite offices or orders within the Church. Apostleship, prophecy and teaching were only functions, whose frequent or regular exercise by one or another, under the inspiration of the Spirit, led his brethern to call him an apostle, prophet or teacher.
But at an early day we find regular officers in this and that local Church, and early in the 2nd century the three permanent offices of bishop, presbyter and deacon existed at any rate in Asia Minor (cf. the Epistles of Ignatius of Antioch). Their rise was due principally to the necessity of administering the charities of the Church, putting an end to disorder and confusion in the religious services, and disciplining offenders. It was naturally to the apostles, prophets and teachers, its most spiritual men, that the Church looked first for direction and control in all these matters. But such men were not always at hand, or sometimes they were absorbed in other duties. Thus the need of substitutes began to be felt here and there, and as a consequence regular offices within the local Churches gradually made their appearance, sometimes simply recognized as charged with responsibilities which they had already voluntarily assumed (cf. 1. Cor. xvi. 15), sometimes appointed by an apostle or prophet or other specially inspired man (cf. Acts xiv. 23; Titus i. 5; 1 Clement 44), sometimes formally chosen by the congregation itself (cf. Acts vi., Did. xi.). These men naturally acquired more and more as time passed the control and leadership of the Church in all its activities, and out of what was in the beginning more or less informal and temporary grew fixed and permanent offices, the incumbents of which were recognized as having a right to rule over the Church, a right which once given could not lawfully be taken away unless they were unfaithful to their trust. Not continued endowment by the Spirit, but the possession of an ecclesiastical office now became the basis of authority. The earliest expression of this genuinely official principle is found in Clement’s Epistle to the Corinthians, ch. xliv. Upon these officers devolved ultimately not only the disciplinary, financial and liturgical duties referred to, but also the still higher function of instructing their fellow-Christians in God’s will and truth, and so they became the substitutes of the apostles, prophets and teachers in all respects (cf. 1 Tim. iii. 2, v. 17; Titus i. 9; Did. 15; 1 Clement 44; Justin’s first Apology, 67).
Whether in the earliest days there was a single officer at the head of a congregation, or a plurality of officers of equal authority, it is impossible to say with assurance. The few references which we have look in the latter direction (cf., for instance, Acts vi.; Phil. i. 1; 1 Clement 42, 44; Did. 14), but we are not justified in asserting that they represent the universal custom. The earliest distinct evidence of the organization of Churches under a single head is found in the Epistles of Ignatius of Antioch, which date from the latter part of the reign of Trajan (c. 116). Ignatius bears witness to the presence in various Churches of Asia Minor of a single bishop in control, with whom are associated as his subordinates a number of elders and deacons. This form of organization ultimately became universal, and already before the end of the 2nd century it was established in all the parts of Christendom with which we are acquainted, though in Egypt it seems to have been the exception rather than the rule, and even as late as the middle of the 3rd century many churches there were governed by a plurality of officers instead of by a single head (see Harnack, Mission und Ausbreitung des Christenthums, pp. 337 seq.). Where there were one bishop and a number of presbyters and deacons in a church, the presbyters constituted the bishop’s council, and the deacons his assistants in the management of the finances and charities and in the conduct of the services. (Upon the minor orders which arose in the 3rd and following centuries, and became ultimately a training school for the higher clergy, see Harnack, Texte und Untersuchungen, ii. 5; English translation under the title of Sources of the Apostolic Canons, 1895.)
Meanwhile the rise and rapid spread of Gnosticism produced a great crisis in the Church of the 2nd century, and profoundly affected the ecclesiastical organization. The views of the Gnostics, and of Marcion as well, seemed to the majority of Christians destructive of the gospel, and it was widely felt that they were too dangerous to be tolerated. The original dependence upon the Spirit for light and guidance was inadequate. The men in question claimed to be Christians and to enjoy divine illumination as truly as anybody, and so other safeguards appeared necessary. It was in the effort to find such safeguards that steps were taken which finally resulted in the institution known as the Catholic Church. The first of these steps was the recognition of the teaching of the apostles (that is, of the twelve and Paul) as the exclusive standard of Christian truth. This found expression in the formulation of an apostolic scripture canon, our New Testament, and of an apostolic rule of faith, of which the old Roman symbol, the original of our present Apostles’ Creed, is one of the earliest examples. Over against the claims of the Gnostics that they had apostolic authority, either oral or written, for their preaching, were set these two standards, by which alone the apostolic character of any doctrine was to be tested (cf. Irenaeus, Adv. Haer. i. 10, iii. 3, 4; and Tertullian, De Prescriptione Haer. passim). But these standards proved inadequate to the emergency, for it was possible, especially by the use of the allegorical method, to interpret them in more than one way, and their apostolic origin and authority were not everywhere admitted. In view of this difficulty, it was claimed that the apostles had appointed the bishops as their successors, and that the latter were in possession of special divine grace enabling them to transmit and to interpret without error the teaching of the apostles committed to them. This is the famous theory known as “apostolic succession.” The idea of the apostolic appointment of church officers is as old as Clement of Rome (see 1 Clement 44), but the use of the theory to guarantee the apostolic character of episcopal teaching was due to the exigencies of the Gnostic conflict. Irenaeus (Adv. Haer. iii. 3 ff., iv. 26, iv. 33, v. 20), Tertullian (De prescriptione, 32), and Hippolytus (Philosophumena, bk. i., preface) are our earliest witnesses to it, and Cyprian sets it forth clearly in his epistles (e.g. Ep. 33, 43, 59, 66, 69). The Church was thus in possession not only of authoritative apostolic doctrine, but also of a permanent apostolic office, to which alone belonged the right to determine what that doctrine is. The combination of this idea with that of clerical sacerdotalism completed the Catholic theory of the Church and the clergy. Saving grace is recognized as apostolic grace, and the bishops as successors of the apostles become its sole transmitters. Bishops are therefore necessary to the very being of the Church, which without them is without the saving grace for the giving of which the Church exists (cf. Cyprian, Ep. 33, “ecclesia super episcopos constituitur”; 66, “ecclesia in episcopo”; also Ep. 59, and De unitate eccles. 17).
These bishops were originally not diocesan but congregational, that is, each church, however small, had its own bishop. This is the organization testified to by Ignatius, and Cyprian’s insistence upon the bishop as necessary to the very existence of the Church seems to imply the same thing. Congregational episcopacy was the rule for a number of generations. But after the middle of the 3rd century diocesan episcopacy began to make its appearance here and there, and became common in the 4th century under the influence of the general tendency toward centralization, the increasing power of city bishops, and the growing dignity of the episcopate (cf. canon 6 of the council of Sardica, and canon 57 of the council of Laodicea; and see Harnack, Mission und Ausbreitung, pp. 319 seq.). This enlargement of the bishop’s parish and multiplication of the churches under his care led to a change in the functions of the presbyterate. So long as each church had its own bishop the presbyters constituted simply his council, but with the growth of diocesan episcopacy it became the custom to put each congregation under the care of a particular presbyter, who performed within it most of the pastoral duties formerly discharged by the bishop himself. The presbyters, however, were not independent officers. They were only representatives of the bishop, and the churches over which they were set were all a part of his parish, so that the Cyprianic principle, that the bishop is necessary to the very being of the Church, held good of diocesan as well as of congregational episcopacy. The bishop alone possessed the right to ordain; through him alone could be derived the requisite clerical grace; and so the clergy like the laity were completely dependent upon him.