In his important and stimulating article, “Christian Number and Its Implications,” Roman historian Keith Hopkins next begins to think about the implications about the size of the Christian church at different periods.  One point to emphasize is that there was not simply one church.  There were lots of churches in lots of places, and it is a myth to think that they were all one big cohesive bunch.  On the contrary, they were often (as we see in our records) often at odds with each other.

But even more than that, even within one city – if it was large enough (think Rome or Antioch for example) there would have been more than one church.  And why?  Because there would have been too many people to meet in one place.

The first time we have any evidence of a church “building” – that is, what we today normally think of as a church (the Baptist church on the corner; the Methodist church up the street) – is not until the middle of the third Christian century.  Before then (and in many, many places, long after then), Christians simply met either in private homes or in outdoor settings, such as cemeteries (really!).

If there were, say 200 Christians in Rome in the year 120, they couldn’t meet in a single home.  It’s more likely that they would have something like four or five different homes to meet in.  And these would be scattered throughout the city.   How do we know how well these different groups of people —  all calling themselves Christian and considering their community to be a “church” — got along?  Did their leaders see eye to eye with one another?  Did they have different doctrinal views?  Different ways of practicing baptism and the eucharist and worship?  How would we know?  There’s no way to know.

But it’s also hard to know – impossible, really – whether each group had the same policies of inclusion.  In one of these house churches, is it possible that only baptized Christians were “counted” as members of the church, but in others anyone who wanted to show up for a service wascounted?   Were some communities more porous than others?  That seems likely, but how could we know?  We simply lack the kinds of evidence we need.

And that’s because we are lacking adequate texts to guide us.

Here is one of the really fascinating points that Hopkins makes.  First a bit more background: I mentioned earlier the name Adolf von Harnack.  Harnack was one of the most brilliant scholars of Christianity in modern times, an unbelievably erudite and prolific scholar so amazing that one suspects he came from a different planet.  In one of his many, many books, The Mission and Expansion of Christianity in the First Three Centuries, written over a century ago now, Harnack looks at every single surviving reference to Christianity in every surviving literary source that we have.  Through this exhaustive analysis he shows that we have record of about 50 locations with churches in the year 100.

Hopkins thinks that this is far too few.  Surely there were more.  But suppose that it’s right, that there were 50.  We know that churches were sending communications to one another.  Suppose that at a minimum each of these 50 churches was sending (and therefore, on average, receiving) just two letters a year.   That would mean that over the course of a century – say from 50 CE to 150 CE – there were 10,000 Christian letters being sent around (50 churches times 2 letters times 100 years).   Now that’s a lot of letters.  And how many of those Christian communications from before 150 CE do we have still today?  We have about 50.

And the reality is that there would have been way more than 50 churches, because that 50 is counting just one church in Rome, one in Antioch, etc.  Plus there are undoubtedly churches in places for which we have no record.   So how many Christian letters were there in this period?  20,000?  30,000?   We have only 50.

Harnack calculated, on the basis of every single piece of surviving literary evidence, that by the year 180 there were some 100 cities or towns that had a Christian church.  Let’s say, proposes Hopkins, that we don’t have a record of half of the churches that actually did survive, so that there were 200.  This is just a blind guess, nothing more – but it’s double the number for which we actually have any evidence.  So here’s something else to think about: we know of about 2000 towns in the empire.   If there were 200 towns that had Christians in them at the time, this would mean that in 180 CE 1800 out of 2000 towns in the empire had no Christian presence.

I don’t know about you, that strikes me as both surprising and a bit troubling.  Can it be true?  We normally think of Christianity spreading massively through the Empire at a very fast rate.   And maybe it was.  But if it was growing instead simply at a steady rate over time, then maybe it’s true that by 180 (150 years after Jesus’ death!) only 10% of the towns and cities in the empire had a Christian church or more in them.

If there were many more, then think about how many, many thousands of letters between churches we don’t have.   Or, if these churches – say, most of them – -did not write letters to one another, then how can we be sure that these various churches were at *all* like each other?  Wouldn’t each of them have developed its theological views and Christian practices differently, if they were all in relative isolation from one another?  Could visitors from one church to another have helped to guarantee a standard set of beliefs and practices?  Presumably that would help – but would a church in, say 150 CE, be inclined to change how it had worshiped and what it believed because some outsider came and indicated that in his home church they though and behaved differently?

The more I think about the Christianization of the empire, the more I realize we simply don’t know…