It held together for a generation or so but it was always a fragile alliance that eventually disintegrated. We see the cracks already coming to the surface in Paul's letter to the Galatians:
Now when Peter had come to Antioch, I withstood him to his face, because he was to be blamed; for before certain men came from James, he would eat with the Gentiles; but when they came, he withdrew and separated himself, fearing those who were of the circumcision. And the rest of the Jews also played the hypocrite with him, so that even Barnabas was carried away with their hypocrisy. [Gal 2:11-13]
I would suggest that the evidence indicates that the apostolic church remained and at least the Ebionites broke away, which really is not that much of a surprise. I have studied this extensively in the past and have found no reason to suspect that the apostolic church "disintegrated". Again, the mark of the "one body" was the issue of apostolic succession.
What we find reported in Acts and elsewhere is a mentioning of various disputes that arose and how they supposedly got resolved. Now, some consider this a "whitewash", and I guess it's impossible to prove otherwise, but this becomes difficult to swallow because not all the Jews in the early church suddenly croaked, only leaving gentiles.
On top of this, we really don't know much about the Ebionites, especially since we simply don't know how they formed or acted in the 1st century since the first writings about them are not until the 2nd century.
Critical scholars believe the account given in Acts is something of a whitewash and that the disparate groups were not as on friendly terms as that account would have it.
Hey, they were Jews.
Basically you had a faction that was very dedicated to full Torah observance led by James, a faction led by Paul who did not believe Gentiles should be forced to adhere to Jewish law, and a bunch of people somewhat on the fence (like Peter). A compromise may have been struck requiring the Gentile converts to observe a version of Noachide law but tensions still existed among the different groups and sometimes erupted as is recounted in Galatians. Even in Acts itself we see this:...
But did James eventually reconcile and rejoin Peter, Paul, and the others? Can't say. Also, it does little good to quote any of the scriptures dealing with the Ebionites since they themselves only recognized one gospel ("Aramaiic Matthew"), which we don't have a copy of, which makes it even harder yet.
So basically we have these two groups with different ideas trying to coexist as one church. It works mainly because the Jewish Torah observant faction is based in Jerusalem and the other groups are remote and in Gentile territory. But the problems arise when the two groups try to come together as one. How can they even eat together?
Except the're no evidence that all or most of the Jewish followers suddenly left the apostolic church and all went to the Ebionites.
When this fragile confederation finally disintegrates is when we find two separate churches, a non-observant Gentile church and a fully observant Jewish one. The former gains the upper hand and eventually even declares the latter heretical and it fades away into history.
One simply cannot call it a "non-observant gentile church" for reasons mentioned above. Nor does it seem to make sense since we know there were Jews who lived on to the end of the 1st century (John, for just one example) and who had appointed leaders that went on into the 2nd century.
Did you have something specific in mind? Do you mean eating with Gentiles or eating meat sacrificed to other gods as Paul did? Otherwise I'm not seeing it.
Peter was eating with gentiles would have been an absolute no-no back then, and we see his confrontation with James over that. Also, Peter's vision on all animals being "clean" is just another example. BTW, isn't it possible that James eventually came around to agree with Peter, Paul, and Mary, singing the same tunes together?
If anything that would be a minor influence in my estimation. it certainly had no impact on those like James who were "zealous for the Law". And even Paul could be quite legalistic in his own way. I think it had to do more with the issue of whether or not Gentiles needed to observe Jewish law and if not how could these two groups coexist as one.
The fact that it was even in question should tell us something, and that simply is that there's some controversy even in the minds of the apostles. If it wasn't a controversial issue then why does it even show up in Acts? Why is it that Paul's writings were actually the most widely circulated and accepted in the 1st century church? Why is it that both Peter and Paul end up in Rome? Etc.
