And what is wrong with being set apart from the Jews? Didn't Jesus himself start that tradition, which was continued by the apostles? Christian persecution was a given before Constantine put a stop to it by making Christianity legitimate. How would distancing themselves from the Jews help their cause?
Jerusalem was in gentile hands before and after the destruction of the Temple - but while Christians could be reasonably tolerated as a sect of Judaism, after the Jewish patronage had been removed, they were persecuted simply as atheists (i.e. not believing in the Roman gods - as we see in Pliny's letter to Emperor Trajan). There is also no "new gentile administration" in the church, since it fled from Jerusalem intact (as God promised it would, and Jesus assures us in Revelations - 90AD).
a. First off, I should have said that the gentile administration took over after the destruction by Hadrian, not the 70 AD one. They fled intact to Pella, as you said, given Jesus' warning in Matthew 24. Eusebius records a Jewish administration before and after 70 AD. Sorry for the mix-up. You are quite right about the information on the flight.
Eusebius notes the first non-circumcision bishop:
“And thus, when the city had been emptied of the Jewish nation and had suffered the total destruction of its ancient inhabitants, it was colonized by a different race, and the Roman
city which subsequently arose changed its name and was called Aelia, in honor of the emperor Aelius Adrian. And as the Church there was now composed of Gentiles, the first one to assume the government of it after the bishops of the circumcision was Marcus.” Eusebius, HE 4, 6,4,
In regards to the passover, since I still can’t find any primary source reference online to Epiphanius’ material I will just quote a section where it is referenced in Bacchiocchi’s Sabbath to Sunday,
The Bishop makes specific reference to the fifteen Judaeo-Christian
bishops who administered the Church of Jerusalem up to A.D. 135 and who
up to that time had practiced the Quartodeciman Passover since they based
themselves on a document known as the Apostolic Constitutions— diataseis
ton apostolon— where the following rule is given: “you shall not change the
calculation of time, but you shall celebrate it at the same time as your brethren
who came out from the circumcision. With them observe the Passover.”
b. As to why they would separate themselves at a later date, first off it is clear that they were not intially distinct as you say. While Jesus emphasized the fulfillment of the Messianic prophecies He did not separate from the Jews. In fact, He told His disciples during His ministry to go ONLY to the Jews. Though He did predict before His assension the evangelizing of the whole world.
Here are a few scriptures to show that they did not separate initially..
Act 18:2 And he found a Jew named Aquila, a native of Pontus, recently come from Italy with his wife Priscilla, because Claudius had commanded all the Jews to leave Rome. And he went to see them.
They were expelled though Christian because they were indistinguishable from them.
Act 24:5 For we have found this man a plague, one who stirs up riots among all the Jews throughout the world and is a ringleader of the sect of the Nazarenes.
Act 24:6 He even tried to profane the temple, but we seized him.
They were treated as a sect of Judaism, just as the Pharisees, etc. were.
Paul himself refers to this:
Act 24:14 But this I confess to you, that according to the Way, which they call a sect, I worship the God of our fathers, believing everything laid down by the Law and written in the Prophets,
Paul identifies himself with the Jews. Since Rome recognized only certain religions there was safety in doing this, but it was also an accurate description. They considered themselves Jews who had seen the fulfillment of their hope, and the inclusion of the gentiles. In fact, they were first called Christians in Antioch, a gentile region. Otherwise they were those who followed the Nazarene sect, or the way.
Rom 11:17 But if some of the branches were broken off, and you, although a wild olive shoot, were grafted in among the others and now share in the nourishing root of the olive tree,
Rom 11:18 do not be arrogant toward the branches. If you are, remember it is not you who support the root, but the root that supports you.
Rom 11:19 Then you will say, "Branches were broken off so that I might be grafted in."
Rom 11:20 That is true. They were broken off because of their unbelief, but you stand fast through faith. So do not become proud, but stand in awe.
Rom 11:21 For if God did not spare the natural branches, neither will he spare you.
Rom 11:22 Note then the kindness and the severity of God: severity toward those who have fallen, but God's kindness to you, provided you continue in his kindness. Otherwise you too will be cut off.
Rom 11:23 And even they, if they do not continue in their unbelief, will be grafted in, for God has the power to graft them in again.
Rom 11:24 For if you were cut from what is by nature a wild olive tree, and grafted, contrary to nature, into a cultivated olive tree, how much more will these, the natural branches, be grafted back into their own olive tree.
In Paul’s mind, and obviously those in Acts 15, the gentiles were “grafted in” to the vine, while the natural branches were broken off for a time.
History records that the Christians mingled with the Jews in the synagogues until at least 80-90 AD, and perhaps to 135. Some see the curses on the Christians in the synagogue as even later, but the point is the same. They were not initially as distinct. Even in the New Testament we see Paul preaching to jews and gentiles alike for weeks on end, sometimes years, in the synagogue.
However, by the 300's, Epiphanius considered the Nazarenes, who were a remnant of the Jerusalem church and followed basically the same practices, to be heretics for keeping the Sabbath and being circumcised. Obviously there was more than just a healthy differentiation. By his standards all of the apostles would have been heretics. Here is his description:
Only in this respect they differ from the Jews and Christians: with the Jews they do not agree
because of their belief in Christ, with the Christians because they are trained in the Law, in
circumcision, the Sabbath, and the other things."
"By birth they are Jews and they dedicate themselves to the Law and submit to
circumcision."
Now whether you think that gentiles should or should not keep the Sabbath, it is quite extreme to say that these Christians were heretics. Even before this Justin Martyr makes reference to those who followed the Sabbaths etc. and only grudgingly said that he might have fellowship with them, but only if they did not try to press their issues on him.
These show a departure from Judaism that was more than warranted. And of course later comments from Chrysostom etc. show that relations only deteriorated.
Some of the factors for this separation might be:
1. There were anti-Jewish measures from 70 AD on, at first financial, and then later more sever. These contributed to separation of Jews along religious and ethnic lines. .
For more information see here this article. It covers the basic facts quickly, but likely puts too much emphasis on one element. If you can overlook the tone, the historical information is helpful.
It also records the connection between this persecution and the expelling of Christians from the synagogues.
http://www.torahresource.com/English%20Articles/Last%20Fiscus%20Judaicus.pdf
2. Because Hadrian made harsh restrictions on the Jews for a time.
Note this passage from a Jewish encyclopedia:
After the dearly bought victory in 135, Hadrian received for the second time the title of "imperator," as inscriptions show. Now only could he resume the building, on the ruins of Jerusalem, of the city Ælia Capitolina, called after him and dedicated to Jupiter Capitolinus. A series of magnificent edifices that Hadrian erected in Jerusalem are enumerated in a source that gathered its information probably from Julianus Africanus ("Chron. Paschale," ed. Dindorf, i. 474; "J. Q. R." xiv. 748). The temple of Jupiter towered on the site of the ancient Temple, with a statue of Hadrian in the interior (Jerome, Comm. on Isaiah ii. 9). The Jews now passed through a period of bitter persecution; Sabbaths, festivals, the study of the Torah, and circumcision were interdicted, and it seemed as if Hadrian desired to annihilate the Jewish people. His anger fell upon all the Jews of his empire, for he imposed upon them an oppressive poll-tax (Appian, "Syrian War," § 50).
Hadrian also prevented them from even entering the city of Jerusalem.
This more severe persecution lasted about three years. But the effects lasted longer. The tax of his predecessors, and his restrictive measures caused a distinction between Jews and Christians in the eyes of the government. And it seems from the church father literature of the time that it also led to a lot of anti-jewish rhetoric around that time within the church.
3. . Due to the persecutions that they were enduring the Christians began at around the same time as Hadrian’s measures, to address apologies to the emperors to try to defend their position. They also made apologies against the Jews. Since the Jews were becoming reviled throughout the empire for their rebellions, etc. it is no wonder that as they tried to reconcile with the empire they likewise tried to distinguish themselves from the Jews.
4. Hard feelings between the Jews and the Christians existed from Nero’s blaming the Christians for the fire in Rome, which many believe was incited by the Jews, for the persecution since the time of Paul, the eventual expulsion of Christians from the synagogues, etc.
5. Since after the destruction of Jerusalem in 70 and 135 the church became predominantly gentile in membership and leadership there was less reminding them of their direct ties to Judaism. And it is significant that the changes in the passover reckoning and in the Sabbath seemed to happen first in Rome. This is where anti-Jewish sentiment was high, and there were the most gentile Christians. We see that the historians say they abandoned Sabbath before others on the basis of tradition, that they fasted on Sabbath when others didn’t ,etc.
While you mention that persecution happened to the Christians, it was not constant. It seemed to go in waves. One of those waves was believed by some Christians to have been spurred by the Jews convincing Nero of their guilt in the fire at Rome.
Back in Palestine, where differences between Christians and Jews were less noticeable there was a real danger of being persecuted along with the jews.
By the time of the councils Christianity was in a position of prominence in the empire, judaism was looked at as the antithesis of Christianity. But this was certainly not the case at first, with the disciples.
Christianity had gone from a group of all Jewish adherents, who observed the Torah, converted Jews in massive numbers, but also worshiped the Messiah, to a group that was antagonistic to Jews, to the Torah, etc. They no longer converted Jews in mass numbers as they used to (even for centuries according to history), because Christianity was now something foreign to Judaism.
The Gentiles who at first were grafted in, were now requiring others to become non-Jews to belong to Christianity, and called people such as the first apostles heretics.
While Paul could say that he wished he was cut off from eternal life for the sake of Israel, Chrysostom on the other hand said they were brute beasts to be killed, that their synagogues were places of devils, etc.
I would say something changed from what was original.
While the gentiles were right in not having to keep all the Mosaic restrictions, as Acts 15 upheld (though they were required to keep a few, according to the requirements of foreigners in the Torah), they were not right to reject everything Jewish, or even to call Jewish Christians heretics. Yet the councils did just that, by declaring that you should not rest on Sabbath, should rest on Sunday, etc.
The church grows, and the need for a collected canon and frequent councils become apparent. The council wasn't some state-run institution disconnected from and possibly undermining the church - they represented the church. Leaders were selected by the clear principles set out by the apostles, and they simply exercized their authority (the "keys" Jesus gave to the church).
And if you take this argument seriously then these heirs of the apostles would have considered the original apostles heretics.
However, I dont' want to give the impression that everything the coucils did was wrong. Certainly it was not. But they were shaped by the times as they were, not just by what the apostles received. A council, for the sake of unity might be necessary. But to assume that everything they do is inspired, or right, or according to apostolic tradition is a stretch.