Part 1 is available here. Part 2 is available here.
KRT: What theological lines can we identify in the earliest Christian communities and how are they presented differently in the Gospels?
AP: Well, one is the way in which Jesus is reimagined and reinterpreted through the Jewish worldview. For some in the church in Jerusalem, for example, which is represented by Jesus' brother and to a lesser extent by Peter and John, Jesus was not God; some in that community believed that Jesus, following Jewish thought as taught by their Master, was human, but very close to the divine. There a whole other line of thinking within in the Roman Empire at that time.
The latter is not a a reinterpretation of Jesus developed by the Jews of Palestine. It was developed by Jews, but they were different. No, the latter was developed by those whose culture and language were Greek-Roman. They were Jewish, but they had a somewhat different mindset than what you would find in Jerusalem per se. These Jews had embraced or grown up accustomed to or influenced by the Gentile religious environment in which they lived and by Gentile thinkers who had given themselves to topics like salvation and immortality. These Jewish Christians basically think about Jesus minus his Jewish features. They transform the Jewish messiah and divine savior into a universal character, whose sacrifice redeemed humanity from sin and extend to them the resurrection from the dead, if they are baptized in his name. The picture is all painted once we see the symbolic reference to eating his body and drinking his blood in the Eucharist.
From who does such a line originate? –Paul of Tarsus, undoubtedly. It is Paul whose writings have been most preserved in the New Testament writings, seven of which were actually written by Paul himself. As Paul travels around planting these communities, he begins incorporating into his own theology elements of pagan religion that were acceptable, forming two different streams of thought in Judeo-Christianity . . . and they fight to the death. Look, we know that they fight. Just remember the letter to the Galatians that describes how a deadly opposition was waged against Paul by the envoy sent from the community in Jerusalem, probably sent by James.
This ideological struggle continues throughout the entire second century, giving rise to a number of different Christianities (approximately eight or nine total). For a description, you can consult my book Cristianismos derrotados. If you could travel back in time to a city somewhere in Asia Minor in the second century, you would find a very Jewish Christianity divided into multiple branches: another that was very Pauline; one that placed a huge importance on women, such as the followers of the Gospel of John; another that was very prophetic following after Montanus; another that believed marriage and sex were impediments to salvation; one that was gnostic, where access to God was granted through special revelation and where the Judeo-Christian God was interpreted from Platonic categories (such group also believed that only they would be saved). And even this last group was divided into multiple different branches, and so it goes.
With all these interpretations, Christianity was better equipped to succeed in the effervescent religious "market" of the Roman Empire. There were lots to choose from. And the Pauline stream of thought was best situated out of all of them because it stripped the Jewish elements out of Jesus and taken the whole eschatological element out of Jesus. He proclaimed that in order to be saved God was not requiring people to keep and accept the old law of Moses, neither circumcision nor the dietary restrictions and other provisions (in total some 635, according to the Mishnah). Basically all they had to do was believe that Jesus was the Messiah, be baptized in his name, and keep his law. This was quite easy and much cheaper than what other religions said people had to do in order to obtain salvation, including the mystery religions where members had to pay initiation dues, etc. So it is not surprising that over the third and fourth centuries all other streams of Christianity declined and gave way to Paul's interpretation of the salvation that is found in Jesus.