This is my reply to Phil in the thread One Holy Universal Church. As I was writing my reply it became too long and too involved to just leave it to me and Phil so I thought I'd share.
While I'm not suggesting that the early fathers believed in papal infallibility necessarily or that they even had an understanding of the papacy like the one we have today, I think "respect" is not adequate to describe their thoughts towards the Roman pontiff as that link I posted (I believe) clearly shows.
Studying the development of beliefs is an important task in determining their truth but it must be done with reason. The Protestant position is that the papacy developed gradually starting probably very late (as you have stated in the middle ages) and is unfounded Scripturally and the early Church didn't believe in it.
Obviously, Catholics see it differently. In my previous post I discussed the Catholicity of the Church in Acts. While Peter's clear prominence (mentioned more than any other apostle in the NT) is already well documented in the gospels, Acts continues this prominence. Much of Acts is centered on the journeys of St. Paul but St. Peter is consistently portrayed as the leading authority of the Church. Why, if he wasn't the rock on which Christ built His Church? (Not a rhetorical question, I don't know the answer and I'm sure you have a response).
Now as for the development of doctrine, yes we do need to pay very close attention. But if, as you say, a doctrine arising from nowhere or only gradually being developed and not pronounced until much later than the NT means it is false... then all Protestant doctrines would be false since they unequivocally arose many hundreds of years after the apostles. The biggest and most indisputable example would be sola fide which any pro-Luther scholar (like Heiko Oberman for example) would agree, never once appeared anywhere before Martin Luther came up with it. A weak argument can be made from the writings of Paul but only if you ignore the rest of Scripture and Paul never actually says it. You cannot argue that this doctrine didnt just come out of nowhere in 1521. So if a doctrine starting late means its false, then Protestantism would be false as well. In that case, maybe the Orthodox Christians are the ones who found the truth.
Nevertheless, as those quotes from that link above show, it did not completely arise out of nowhere in the middle ages. The understanding we have today has been developmental I will concede that. But in the Scriptures we see Peter's prominence and authority, and in the writings of the early fathers through history we see not merely respect for but extreme loyalty and even submission to the Roman pontiff.
Now you said this doctrine arose in the middle ages. Ignoring the quotes from the Fathers linked to above, Bruce Shelley (unambiguously anti-Catholic Church historian) in his book "Church History in Plain Language" on page 133 he says:
"Whatever the absolute claims of church authorities, history indicates that the concept of papal rule of the whole church was established by slow and painful stages"(Again this doesnt mean its wrong even if what he says is true... Getting the Jews to accept Christ has been a much slower and much longer process but...) He goes on to say:
"Leo is a major figure in that process because he provides for the first time the biblical and theological bases of the papal claim. That is why it is misleading to speak of the papacy before his time."Aside from Mr. Shelley being completely wrong in this point (see St. Irenaeus Against Heresies in the late 2nd century for example) Leo was the pope from 440 - 461 AD as attested to by Mr. Shelley's list of popes on page 505. So while even his date is very late for the pronounced beginning of papal rule, it is still much earlier than the middle ages.
On page 136 he goes on to admit:
"At a synod in Rome the next year, the bishops from the West argued: 'The Holy Roman Church takes precedence over the other churches, not on the ground of any synodal decisions, but because it was given the primacy by the words of our Lord and Redeemer in the gospel, when He said: 'Thou art Peter, and upon this rock I will build my Church.''"So now he has contradicted himself in his attempt to prove the issue of primacy to be as late as possible, since he said before that Leo was the first to argue from the Scriptures and he disproves it himself (ignoring the arguments that came before even the synod at Rome). Lets not forget that all this is coming from a book on church history which is very anti-catholic. I read this book while I was still a Protestant and I myself was anti-Catholic. But I remember how surprised I was at his not-so-cleverly disguised contempt for the Catholic Church. So if there's bias in his work (and there is), its in your favor not mine and thats why I quote him.
Back to my point, again even if all of this were true and even if the doctrine wasnt developed until the middle ages that wouldnt make it false. Or how many years do we have in the 'grace period' ending with Christ to nail down a doctrine? I hope its only a few because many Christian dogmas accepted by both Protestants and Catholics came much later.
Notably, the Trinity was never even mentioned until the second century. None of the authors of the New Testament had any knowledge of the doctrine as is made clear by their writings. (Not saying that they opposed it, just that the doctrine had not fully developed to the level of understanding we have today.. that would not come until more than 300 years later). But none of this means that the doctrine is false, I'm sure you will agree. So how can we say "doctrine x appeared y number of years after Christ and was a developed doctrine" when we ourselves believe in other doctrines originating at various intervals and some much later than doctrine x!
Now as for the Trinity, you can look back to Scripture and see the Trinity being taught. You can also look back and see the primacy of Saint Peter.
There's enough 'wiggle room' in history and in Scripture to deny the primacy of the Roman pontiff. It's a matter of faith (and no I'm not saying that if you have as much faith as me you'll belive.). I know many millions of faithful Christians do not believe in the primacy of St. Peter's chair. Much of the disbelief is based on misconceptions though such as the notions that the Pope is seen as sinless or inerrant in everything that comes out of his mouth. Neither of these are true. Some do not believe in it out of a contempt for authority in general. Others understand the doctrine very well but reject it theological grounds. I think though, to reject it on historical grounds is a bit lacking.
Ultimately as we all agree, Christ is the head of the Church, which is His bride. Let us find ways that we can in unison bring glory to His name and keep our brothers and sisters on the straight and narrow path.