With the Jews there is a solid concensus concerning the canon of the Bible.
In a sense they do now, but historically it seems that this really didn't happen for the Tanakh until somewhere in the 4th to 6th century.
Thus was true, as I pointed out, in the first century. We have the witness of scripture to this reality where Paul studied under Gamiel and Gamiel's disciples became one of the strands of Jewish belief.
Your right definitely not in the 1st century, and it seems that it didn't happen until sometime between the 4th and 6th centuries maybe. This process for them was even less documented than the Christian one.
A similar thing is true of both the Ethiopian Orthodox Church and the Coptic Church. They went their separate ways very early in the history of Christianity and, as a result, have been considered by many branches of Christianity to be pariahs, at best, and heretics, at worst, similar to the Nestorians who withered from being a major element of early Christianity to becoming a footnote in Christian history books.
Not the Coptics. Coptics were knee deep in the general history of the Church from the get-go. That didn't change until well when Muslims took over North Africa and suppressed the Coptic Church.
Ethiopia is unique, much like the Indian Church. Both were separated from the main body of Christians in the Roman Empire, and as such they really are very interesting subjects, especially considering that the Indian Church when rediscovered during the Age of Exploration.
As one has said, to the winner belongs the history. In the case of Christianity there has been no clear-cut winner when viewed objectively, although some branches such as yours claim the victory, as well as the right to present their view of the history. The simple thing is to berate and harrass differing branches hopefully into oblivion. As history has shown, neither the Ethiopian Orthodox Churches nor the Coptic Churches appear to be going away any time soon, nor the EOC or the various Protestant churches.
Well hopefully none of the Particular Apostolic Churches go away. I do not pray, and I think it is wrong to do so, for the conversion of any of the Eastern or Oriental Orthodox Churches to convert to Catholicism. There is nothing to convert. They are already Catholics. All members of the Apostolic churches are Catholics. No, the right prayer to make is for the horrible schisms to end, and we enter back into full communion with each other, as Christ would have us.
Concerning Protestants? Yes I do pray for your return to the fullness of faith. Not conversion, because I believe that occurs when one goes from following Satan and the world to following Christ and His Father. This faithful Protestants have already done.
But concerning history, Christ has already won. He won 2000 years ago, and those of us who follow Him and persevere to the end have won as well, no matter what the world throws at us.
The Catholic Church in communion with the Pope is very unique in history, in that there was at one time a whole continent that was Catholic, and devout Catholic at that, so we have been able in a sense blossom in our knowledge and faith to a level no other Particular Church has been able to do. We have also been able to grow not just internally but also externally more than any other Apostolic Church.
Why? Because nearly all the other Particular Churches (Russian and Greek being the only exceptions I can think of), such as the Greek, Coptic, Antiochian, etc, have lived now most of their history being suppressed by Islam. You think about that just for a second, the Patriarchates of Alexandria and Antioch have been under Muslim rule for about 1200 years, the Greek Christians under their rule over 500 years! Not being able to grow externally, due to that suppression, and their believers having every incentive in the world to convert to Islam; it is a miracle by God that they have maintained their existences until today!
That leaves yet another means of addressing the problem, which is to convince the others of the correctness of your position so that they will submit and merge with you, confessing their heresies and errors. This, of course, has been a strategy attempted by virtually all branches of Christianity, not to mention non-Christian religions such as Islam. Without compelling incentives, it does not work.
I follow Catholic teaching on this matter. It is our jobs to be God's instruments and proclaim the good news; but only God can give anyone the grace to convert to Him; and only God can give someone the grace to swim the Tiber to enter the fullness of His faith.
If all else fails, just slaughter members of the other side, knowing that, as heretics, their doom has already been secured and it is merely a matter for you, as administrators of the justice of the Almighty, to rid the earth of this blight. We assuredly see this strategy actively being pursued within Islam today.
Yeah, this has always failed, because those doing the slaughtering are not doing so for godly reasons ever.