How did the early Christians view it?
The first Christians had no doubts about how to determine which claimant, among the many contending for the title, was the true Church. The test was simple: Just trace the apostolic succession of the claimants. The simple procedure worked every time. (Why not try it yourself?)
CLEMENT OF ROME (A.D. 80)
Through countryside and city [the apostles] preached, and they appointed their earliest converts, testing them by the Spirit, to be bishops and deacons of future believers. Nor was this a novelty, for bishops and deacons had been written about a long time earlier....Our apostles knew through our Lord Jesus Christ that there would be strife for the office of bishop. For this reason, therefore, having received perfect foreknowledge, they appointed those who have already been mentioned and afterwards added further provision that, if they should die, other approved men should succeed to their ministry. (Epistle to the Corinthians 42:4-5,44:1-3).
HEGESIPPUS (circa A.D. 180)
When I had come to Rome, I [visited] Anicetus, whose deacon was Eleutherus. And after Anicetus [died], Soter succeeded, and after him Eleutherus. In each succession and in each city there is a continuance of that which is proclaimed by the Law, the Prophets, and the Lord. (Memoirs 4:22:1).
IRENAEUS (inter A.D. 180-199)
It is possible, then, for everyone in every church, who may wish to know the truth, to contemplate the tradition of the apostles which has been made known to us throughout the whole world. And we are in a position to enumerate those who were instituted bishops by the apostles and their successors down to our times, men who neither knew nor taught anything like which these heretics rave about....Surely they wished all those and their successors, to whom they handed on their authority, to be perfect and without reproach. (Against Heresies 3:3:1).
For all these [heretics] are of much later date than are the bishops to whom the apostles handed over the churches, and this fact I pointed out most carefully in the third book. It is of necessity, then, that these aforementioned heretics, because they are blind to the truth, walk in devious paths, and on this account the vestiges of their doctrines are scattered about without agreement or connection. The path of those, however, who belong to the Church goes around the whole world, for it has the firm tradition of the apostles, enabling us to see that the faith of all is one and the same. (Ibid. 5:20:1)
Polycarp was instructed not only by the apostles and conversed with many who had seen Christ, but was also appointed bishop of the church in Smyrna by the apostles in Asia. I saw him in my early youth, for he tarried a long time and when quite old departed this life in a glorious and most noble martyrdom. He always taught those things which he learned from the apostles and which the Church had handed down and which are true. To these things the churches in Asia bear witness, as do also the successors of Polycarp even to the present time. (Ibid. 3:3:4).
It is necessary to obey those who are the presbyters in the Church, those who, as we have shown, have succession from the apostles, those who have received, with the succession the episcopate, the sure charism of truth according to the good pleasure of the Father. But the rest, who have no part in the primitive succession [of bishops] and assemble wheresoever they will, must be held in suspicion....The true gnosis [knowledge] is the doctrine of the apostles, and the ancient organization of the Church throughout the whole world, and the manifestation of the body of Christ according to the succession of bishops, by which succession the bishops have handed down the Church which is found everywhere. (Ibid. 4:26,33:8).
FIRMILIAN (inter A.D. 255-256)
But what is his error and how great his blindness...who does not remain on the foundation of the one true Church which was founded upon the rock by Christ, can be learned from this, which Christ said to Peter alone, "Whatsoever things you shall bind on earth shall also be bound in heaven"; and by this, again in the Gospel, when Christ breathed upon the apostles alone, saying to them, "Receive the Holy Spirit. If you forgive any man his sins they shall be forgiven, and if you retain any man's sins they shall be retained." The power of forgiving sins was given to the apostles and the churches which these men, sent by Christ, established and to the bishops who succeeded them by being ordained in their place. (Epistle to Cyprian 75:16).
JEROME (inter 374-379 A.D.)
Far be it from me to speak adversely of any of these clergy who, in succession from the apostles, confect by their sacred word the Body of Christ and through whose efforts also it is that we are Christians. (Epistle to Heliodorus 14:8).
GREGORY I (A.D. 590-591)
The disciples receive as their lot the preeminence of celestial judgment, so that, in God's stead, they retain sins for some and for some they forgive them [John 20:22-23]....Certainly it is now the bishops who hold their place in the Church. They receive the authority of binding and loosing, who have as their lot a degree of governing. It is a magnificent honor, but that honor carries with it a heavy burden. (Homilies on the Gospels 2:26:4).
Taken from "The Fathers Know Best" from the Sept. 1992 issue of This Rock, published by Catholic Answers, P.O. Box 17490, San Diego CA 92177. (619) 541-1131. Permission to reproduce is granted provided textual integrity is retained.