SPQR: A History of Ancient Rome:
But to a remarkable and in some ways unexpected degree, the Jews managed to operate within Roman culture. For the Romans, Christianity was far worse. First, it had no ancestral home. In their ordered religious geography, Romans expected deities to be from somewhere: Isis from Egypt, Mithras from Persia, the Jewish god from Judaea. The Christian god was rootless, claimed to be universal and sought more adherents. All kinds of mystical moments of enlightenment might attract new worshippers to (say) the religion of Isis. But Christianity was defined entirely by a process of spiritual conversion that was utterly new. What is more, some Christians were preaching values that threatened to overturn some of the most fundamental Greco-Roman assumptions about the nature of the world and of the people within it: that poverty, for example, was good; or that the body was to be tamed or rejected rather than cared for. All these factors help to explain the worries, confusion and hostility of Pliny and others like him. At the same time, the success of Christianity was rooted in the Roman Empire, in its territorial extent, in the mobility that it promoted, in its towns and its cultural mix. From Pliny’s Bithynia to Perpetua’s Carthage, Christianity spread from its small-scale origins in Judaea largely because of the channels of communication across the Mediterranean world that the Roman Empire had opened up and because of the movement through those channels of people, goods, books and ideas. The irony is that the only religion that the Romans ever attempted to eradicate was the one whose success their empire made possible and which grew up entirely within the Roman world.
More: read SPQR: A History of Ancient Rome
“… the only religion that the Romans ever attempted to eradicate …”
Wikipedia doesn’t make it sound like Roman attempts to eradicate Christianity were very consistent or pervasive.
“There was no empire-wide persecution of Christians until the reign of Decius in the third century.[3] Provincial governors had a great deal of personal discretion in their jurisdictions and could choose themselves how to deal with local incidents of persecution and mob violence against Christians. For most of the first three hundred years of Christian history, Christians were able to live in peace, practice their professions, and rise to positions of responsibility. Only for approximately ten out of the first three hundred years of the church’s history were Christians executed due to orders from a Roman emperor”
https://en.wikipedia.org/wiki/Anti-Christian_policies_in_the_Roman_Empire
The Romans really admired old things. Judaism was an ancient religion and therefore legitimate. But Christianity to them was like Mormonism or Scientology to us – it seemed like they were just making stuff up and Romans were not PC so they were willing to call the Christians on it.
Could it be that the persecution of Christians began when the people in power realized that the Christian mission could finally result in a take-over? A bit too late then, as it seems.
Early Christianity took its roots from the Jewish community and Jewish scriptural tradition, extending its reach then into the Gentile communities around Asia Minor, Egypt, Greece and Rome. Unlike Judaism, which was not a proselytizing tradition and which had both an ethnic, linguistic, cultural and territorial home, Christianity was fixed by none of those constraints and could and did spread quickly to towns and cities that differed widely from one another. In that sense, it represented to some a competitor to Roman culture and its traditions, a culture that was weakening as its empire expanded.