Christianity started small and grew big. What a lot of us don't seem to realise is just how small. Both Keith Hopkins and Rodney Start estimate that there were less that 10,000 Christians in an Empire of 60 million in 100AD. Let's think about what that means.
First, the old canard about why pagan authors said so little about Christian becomes rather an obvious fallacy. One person in 6000 was a Christian or less than 0.02%. There were so few of them that almost no one would notice their existence. Even though they were preponderantly situated in towns so probably a bit more concentrated, that was no reason for patrician Romans, who preferred to lounge around on their country estates, to take any notice of them. What's more, there were about 6 million Jews with whom the Christians were easily enough confused to lack even an identity of their own to most Romans. Tacitus claim that a huge multitude were killed by Nero becomes clear hyperbole (but fairly typical of Tacitus). I doubt the number exceeded a hundred and many of them might well have been Jews caught up in the wrong place at the wrong time. I doubt Nero would care.
Second, it tells us something about the paucity of early Christian writing. It is no longer believed that early Christianity was primarily a poor persons' religion. Better to assume that it was broadly representative of the population as a whole with less country dwellers and more women. Estimates for literacy rates in the Roman world vary but no one suggests that more than 30% of free citizens could write their names. The total who could write a piece of theology in Greek must be a whole lot less - only about 1%. This means it is hardly surprising that Mark's Greek is poor but he was the only guy around who could do the job. Likewise, most Christian communities would have had one person at most who could write well. With such a small literary base, we would not expect many texts. Certainly, claims that there were loads of early Gospels later rejected by the institutional church are exaggerations (so is Luke's claim at the start of his Gospel although he may not have been referring to written accounts).
We inevitably have to speculate but we do need to bear in mind that when we read about the early church, just how few of them their were.
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