According to International Theological Commission (ITC), conflicts could not always be avoided between individuals among the New Testament communities; Paul appealed to his apostolic authority when there was a disagreement about the Gospel or principles of Christian life. How the development of apostolic government developed is difficult to say accurately because of the absence of certain documents. ITC says that the Apostles or their closest assistants or their successors directed the local colleges of episkopoi and presbyteroi by the end of the first century; while by the beginning of the second century the figure of a single bishop, as the head of the communities, appears explicitly in the letters of Ignatius of Antioch (c. 35-107). In the Epistle to the Smyrnaeans, Ignatius wrote about three degrees ministry:
"See that you all follow the bishop, even as Jesus Christ does the Father, and the presbytery as you would the apostles; and reverence the deacons, as being the institution of God. Let no man do anything connected with the Church without the bishop."
Ramsey says that the doctrine was formulated in the second century in the first of the three senses given by him, originally as a response to Gnostic claims of having received secret teaching from Christ or the apostles; it emphasised the publicmanner in which the apostles had passed on authentic teaching to those whom they entrusted with the care of the churches they founded and that these in turn had passed it on to their successors. Ramsey argues that only later was it given a different meaning, a process in which Augustine (Bp of Hippo Regis, 395–430) played a part by emphasising the idea of "the link from consecrator to consecrate whereby the grace of order was handed on."
Writing in about AD 94, Clement of Rome states that the Apostles appointed successors to continue their work where they had planted churches and for these in their turn to do the same because they foresaw the risk of discord: "Our Apostles, too, by the instruction of our Lord Jesus Christ, knew that strife would arise concerning the dignity of a bishop; and on this account, having received perfect foreknowledge, they appointed the above-mentioned as bishops and deacons: and then gave a rule of succession, in order that, when they had fallen asleep, other men, who had been approved, might succeed to their ministry." According to Eric G. Jay, the interpretation of his writing is disputed, but it is clear that he supports some sort of approved continuation of the ministry exercised by the apostleswhich in its turn was derived from Christ.
Hegesippus and Irenaeus introduce explicitly the idea of the bishop's succession in office as a guarantee of the truth of what he preached in that it could be traced back to the apostles. And they produced succession lists to back this up. That this succession depended on the fact of ordination to a vacant see and the status of those who administered the ordination is seldom commented on. Woollcombe also states that no one questioned the apostolicity of the See of Alexandria despite the fact that its Popes were consecrated by the college of presbyters up till the time of the Council of Nicaea in 325. On the contrary, other sources clearly state that Mark the Evangelist is the first bishop of Alexandria (Pope of Alexandria), then he ordained Annianus as his successor bishop (2nd Pope) as told by Eusebius (Historia Ecclesiastica 2.24.1).
James F. Puglisi, director of Centro Pro Unione, made a conclusion about Irenaeus' writings: "the terms episkopos and presbyteros are interchangeable, but the term episkopos [bishop] is applied to the person who is established in every Church by the apostles and their successors".According to Eric G. Jay, Irenaeus also refers to a succession of presbyters who preserve the tradition "which originates from the Apostles".And later goes on to speak of their having "an infallible gift of truth" [charisma veritatis certum]. Jay comments that this is sometimes seen as an early reference to the idea of the transmission of grace through the apostolic succession which in later centuries was understood as being specifically transmitted through the laying on of hands by a bishop within the apostolic succession (the "pipeline theory"). He warns that this is open to the grave objection that it makes grace a (quasi)material commodity and represents an almost mechanical method of imparting what is by definition a free gift. He adds that the idea cannot be squeezed out of Irenaeus' words.
Writing a little later, Tertullian makes the same main point but adds expressly that recently founded churches (such as his own in Carthage) could be considered apostolic if they had "derived the tradition of faith and the seeds of doctrine" from an apostolic church. His disciple, Cyprian (Bishop of Carthage 248–58) appeals to the same fundamental principle of election to a vacant see in the aftermath of the Decian Persecution when denying the legitimacy of his rigorist rival in Carthage and that of the anti-pope Novatian in Rome; however, the emphasis is now on legitimating Cyprian's episcopal ministry as a whole and specifically his exclusive right to administer discipline to the lapsed rather than on the content of what is taught. Cyprian also laid great emphasis on the fact that any minister who broke with the Church lost ipso facto the gift of the Spirit which had validated his orders. This meant that the minister would have no power or authority to celebrate an efficacious sacrament.
Apostolic succession is the method whereby the ministry of the Christian Church is held to be derived from the apostles by a continuous succession, which has usually been associated with a claim that the succession is through a series of bishops. This series was seen originally as that of the bishops of a particular see founded by one or more of the apostles. According to historian Justo L. González, apostolic succession is generally understood today as meaning a series of bishops, regardless of see, each consecrated by other bishops, themselves consecrated similarly in a succession going back to the apostles. According to the Joint International Commission for Theological Dialogue between the Catholic Church and the Orthodox Church, "apostolic succession" means more than a mere transmission of powers. It is succession in a Church which witnesses to the apostolic faith, in communion with the other Churches, witnesses of the same apostolic faith. The "see (cathedra) plays an important role in inserting the bishop into the heart of ecclesial apostolicity", but, once ordained, the bishop becomes in his Church the guarantor of apostolicity and becomes a successor of the apostles.
Those who hold for the importance of apostolic succession via episcopal laying on of hands appeal to the New Testament, which, they say, implies a personal apostolic succession (from Paul to Timothy and Titus, for example). They appeal as well to other documents of the early Church, especially the Epistle of Clement. In this context, Clement explicitly states that the apostles appointed bishops as successors and directed that these bishops should in turn appoint their own successors; given this, such leaders of the Church were not to be removed without cause and not in this way. Further, proponents of the necessity of the personal apostolic succession of bishops within the Church point to the universal practice of the undivided early Church (up to AD 431), before being divided into the Church of the East, Oriental Orthodoxy, the Eastern Orthodox Church and the Roman Catholic Church. Christians of the Roman Catholic, Orthodox, Old Catholic, Anglican, Moravian, and Scandinavian Lutheran traditions maintain that "a bishop cannot have regular or valid orders unless he has been consecrated in this apostolic succession." Each of these groups does not necessarily consider consecration of the other groups as valid.
However, some Protestants deny the need for this type of continuity, and the historical claims involved have been severely questioned by them; Eric G. Jay comments that the account given of the emergence of the episcopate in chapter III of the encyclical Lumen Gentium (1964) "is very sketchy, and many ambiguities in the early history of the Christian ministry are passed over".