Depends on who's scholarship one is reading. The fact of the matter is that there was a continuum that led from Jesus to the apostles and to who the apostles later appointed as evidenced in Acts and some of the epistles.
The consensus in mainstream scholarship, is that Christianity formed, in a separate form from Judaism, after the destruction of the Temple in 70 C.E. The early church period is then measure from there.
There is a continuum for sure. The power went from Jesus, to James, Peter, and John. And from there it split incredibly. There were multiple factions that emerged, which Paul even criticizes.
James was the political leader of the Way, but Peter was the spiritual leader, and when Paul comes to the Twelve, it's Peter whom he deals with, not James. Matter of fact, when the apostles are listed, Peter's name is almost always first, and sometimes it just reads "Peter and the others".
There is no suggestion that James was just a political leader or that Peter was the spiritual leader. Yes, Peter is often mentioned first, but Acts and Paul both state that Paul and Peter had some sort of relationship anyway. Both also agree that James was at the head. There is no distinction between a spiritual leader and political leader there.
And there shouldn't be a difference. Looking at the common practice at that time, spiritual and political leaders were the same. Jesus was both a spiritual leader, who also was seen as a potential political leader. John the Baptist fits the mold as well. As do the Roman Emperors, or any of the Jewish Kings. The two went hand in hand.
Since the Way was already walking away from strict adherence to the Law shortly after Jesus died, and since the Twelve would have tried to follow Jesus' teachings as close as possible, what Jesus taught must have led up to these changes vis-a-vis the Law. It's unimaginable that they would have defied him if he taught that strict adherence to the Law was a must. The Law is a vital necessity within normative Judaism, so Jesus had to have opened the door in some way to have the Twelve walk away from the letter of the Law.
We know virtually nothing about "the Way." All we really know is that the Way is one of various names in which the Jesus movement was called, and that it was led by James, Peter, and John. It was a Jewish movement at the core, but at sometime, it allowed for Gentiles to also enter in. We don't know if they were walking away from strict adherence to the Law shortly after Jesus died. We really don't hear anything about the movement until a number of years later, when Paul first mentions the movement briefly. And at that time, when Paul first interacts with them, they are still quite strict.
However, Judaism, at that time, was always open to Gentiles to a point. There were people called God-fearers who were on the outside. So allowing Gentiles to get into the mix wasn't even straying from Judaism.
We also don't know how closely they would have followed the teachings of Jesus, especially since they had to deal with a lot that Jesus never mentioned. As time moved on, the entire movement had to begin rethinking the message. And changing what Jesus said wasn't a big deal. He wasn't seen as God. He was seen as a human, who was fallible.
A lot of your argument though relies on ignoring what Jesus said, and instead assuming he had to have said something because later people believed it.
It is probable that just after the first decade or so of the church, that might be true, but definitely not after that.
That was my point. To begin with, one had to convert to Judaism. Later on, that became lax, until the movement was removed from Judaism.
IMO, Paul sees a problem, namely how does the church mesh two very different elements, namely the Jewish branch that adheres closely to the Law, versus the "God-Fearers" (gentiles) that didn't? How do they conduct the Agape Meal? kosher? (remember that James caught Peter eating cheeseburgers with gentiles
) What about their kids because conversion to Judaism was a requirement for Jewish marriage. observant or not?
IMO, Paul figured out that it couldn't be done, namely have two different groups operating under two different sets of rules, but still trying to be of "one body". The early church believed that their central teacher was Jesus, and so it had to be Jesus that opened the door on such a change, and I believe it comes from his very liberal attitude towards the Law itself ("law of love"). There's simply no logical way that the Twelve would have abandoned any of the Mosaic Law if Jesus hadn't somehow opened that door.
Interesting conversation.
There was no need to open any door. In Jeremiah (I believe that's the book) we see an OT prophet saying that at the end of times, all nations will bow to God. Paul saw himself living in the end times. So much so that various churches that he wrote to already believed that they had been resurrected. That in itself had already opened the door. The believe that the end was near was everything Paul needed in order to spread the message to the Gentiles, as he believed Judaism encouraged. And we know Paul was thinking in that manner as he alludes to it multiple times.
I agree though, a very interesting conversation.