The Diaspora
Paul was constantly at risk during his travels to preach the gospel.
Formation And Struggles: The Birth of the Church AD 33-200, by Veselin Kesich
2 Corinthians 11: 24 From the Jews five times I received forty stripes minus one. 25 Three times I was beaten with rods; once I was stoned; three times I was shipwrecked; a night and a day I have been in the deep; 26 in journeys often, in perils of waters, in perils of robbers, in perils of my own countrymen, in perils of the Gentiles, in perils in the city, in perils in the wilderness, in perils in the sea, in perils among false brethren
By the first century, about four to five million diaspora Jews made up about seven percent of the population of the Roman Empire. This compared to about 750,000 Jews in Palestine proper. They lived throughout the empire, but the chief centers included Babylonia, Syria, Asia Minor, and Egypt. The apostle Paul was himself born in Tarsus, a city on the southeastern coast of Asia Minor.
Babylonian Jews had roots that dated back to the captivity. Jews were allowed to return to Jerusalem, but many remained. They would remain in contact with Jerusalem and retain Aramaic. Yet they disagreed on some key points: they refused the idea that the law could not be observed outside of Jerusalem, even producing their own legal commentaries on Judaism; they refused to support the Jerusalem Jews in their two wars against Rome in the first and second centuries.
As an added expression of their displeasure, the Babylonian diaspora stopped extending financial support to the poorer Jewish communities of Palestine after AD 70.
Egypt was home to Jewish communities even before the conquest of Alexander the Great. In the Hellenistic period, their numbers would grow, especially in the newly founded city of Alexandria. According to Philo, a million Jews lived in Egypt – this out of a population of perhaps eight million.
Syria also had a population of one million Jews, this out of a total seven million population. A large number of these lived in Antioch.
There were also many Jews in Rome – expelled in 139 BC, yet many brought back as slaves after Pompey conquered Jerusalem in 63 BC. Vespasian brought slaves after 70 AD.
In his Life of Claudius (AD 41-54) Seutonius writes that “The Jews were constantly making disturbances at the instigation of Crestus,” and for this reason the “emperor expelled them from Rome.”
We see something of this event reflected by Luke:
Acts 18: 1 After these things Paul departed from Athens and went to Corinth. 2 And he found a certain Jew named Aquila, born in Pontus, who had recently come from Italy with his wife Priscilla (because Claudius had commanded all the Jews to depart from Rome); and he came to them.
It is implied that the conflicts in Rome were between two groups of Jews in the Jewish synagogues: Christians of Jewish origins and their non-Christian Jewish counterparts were not yet separated and the Romans could not, in any case, tell one group from the other.
Throughout the empire, the diasporan Jews lived primarily in cities. Under Julius Caesar, special privileges were granted to them. While Roman citizens would object to these privileges, the Roman authorities demanded compliance.
Gentiles were drawn to some of the Jewish practices, adopted even without formal conversion. These are referred to in Acts as “worshippers of God,” or “God-fearing people.”
Paul was not the first to preach to Gentiles. Many of the communities he visited had Gentile converts before Paul ever arrived. In my view, it seems likely that one reason for the rapid expansion of Christianity is given in the book of Acts:
Acts 2: 5 And there were dwelling in Jerusalem Jews, devout men, from every nation under heaven.
They would hear Peter’s sermon, and return to their homes. In any case, Paul would find a home in which to stay in the communities he visited – Corinth and Ephesus, two early on. He would warn these converts to expect hostility – from both Gentiles and Jews. it was a foreshadowing of the protection that would be lost once the Christian Jews lost the protection of the synagogue.
Thus, in the first two centuries, Christians would meet in “house churches.” There would be several such house churches in each city with Christians, as one house was not large enough for the local community. Apparently, there would be conflicts between these house churches, as evidenced by Paul in his first letter to the Corinthians:
1 Corinthians 1 10 Now I plead with you, brethren, by the name of our Lord Jesus Christ, that you all speak the same thing, and that there be no divisions among you, but that you be perfectly joined together in the same mind and in the same judgment. 11 For it has been declared to me concerning you, my brethren, by those of Chloe’s household, that there are contentions among you. 12 Now I say this, that each of you says, “I am of Paul,” or “I am of Apollos,” or “I am of Cephas,” or “I am of Christ.” 13 Is Christ divided? Was Paul crucified for you? Or were you baptized in the name of Paul?
My aside: this is why I remain frustrated about the battle of the baptisms today, and the practice of withholding the Eucharist because one wasn’t baptized in the right “church.” It’s also why I am not a fan of the idea of church “membership.” But enough of that…
The Eucharist and Baptism were already practiced, and Paul, through his work and his letters, would reinforce both. Hierarchical structures were also evident early on, for example evidenced in his greeting to “bishops and deacons” in his letter to the Philippians.
Conclusion
Galatians 3: 26 For you are all sons of God through faith in Christ Jesus. 27 For as many of you as were baptized into Christ have put on Christ. 28 There is neither Jew nor Greek, there is neither slave nor free, there is neither male nor female; for you are all one in Christ Jesus. 29 And if you are Christ’s, then you are Abraham’s seed, and heirs according to the promise.
In this lies, perhaps, Paul’s most revolutionary statement: in Christ, no such distinctions exist, and in Christ, you are all of Abraham’s seed. A challenge both to the hierarchical order of Rome and to the chosen-ness of the Jews. No wonder he was often persecuted.
Christ’s Church was open to all, and in Christ’s Church all are equal before God.

“My aside: this is why I remain frustrated about the battle of the baptisms today, and the practice of withholding the Eucharist because one wasn’t baptized in the right “church.” It’s also why I am not a fan of the idea of church “membership.” But enough of that…”
My interest in the RCC was fueled by a [bad] Catholic priest who opened the Eucharist to all baptized believers at a wedding!
Confession is another point at which I’ve seen deviation from what’s ordered. Once a year at some places in the USA. I’ve seen group absolution when the line for confession is too long and the Mass needs to begin. The intention to confess was there …