Thank you very much for accepting, as the answer to your question, the
material I located. I have reposted the information below, with an
additional source that I think you'll find interesting.
"According to the World Christian Encyclopedia (1982), it is estimated
that by A.D. 100 there were 1 million Christians in the Roman Empire
out of a population of 181 million. This means that by the end of the
first century less than 1 percent of the population (0.6% to be exact)
Andrews University: Personal pages of Samuele Bacchiocchi, Ph. D.
"Christianity began in Jerusalem when disciples of Jesus of Nazareth
proclaimed that he was the expected Messiah. The movement spread
slowly) while Jesus was alive, but after Jesus' death it spread more
rapidly. The diffusion was greatly assisted by Christian preachers and
missionaries. It spread first to Samaria (in northern ancient
Palestine), then to Phoenicia to the north-west, and south to Gaza and
Egypt. Afterwards it was adopted in the Syrian cities of Antioch and
Damascus, then subsequently in Cyprus, modern Turkey, modern Greece,
Malta and Rome. It spread fast, and numbers quickly grew. Within the
first century there were an estimated million Christians, comprising
less than one per cent of the total world population."
Lancaster University: Personal pages of Chris Park
"Determination of the place, size, growth rate, commitment, and
faction of early Christian communities remains problematic if not
impossible... Such estimates involve a certain degree of speculation
and lack of precision. Moreover, in an overall population sense the
term "Christians" refers to its membership in an all-inclusive way.
The deeply committed or observant probably would have been
significantly less. Perhaps at most no more than 10% of the total were
actually practicing Christians. At best, based upon today?s knowledge,
developing reasonable projections of Christian population growth are
not plausible beyond the dyad of Christians of Jewish stock and
Christians of Gentile stock. Developing these projections, however,
has some probative value in considering the matter of the Greco-Roman
Gentile Church overtaking and eventually overwhelming
BibArch: Estimates for Late Roman Period
While this excerpt from a letter of Pliny the Younger does not provide
actual figures, it does indicate that, only eighty years after the
crucifixion of Christ, Christianity had spread to the point that it
was causing a notable stir in the Roman Empire:
"Pliny the Younger, governor of the Roman province of Bithynia (on the
north coast of modern Turkey), wrote to emperor Trajan (r. 98--117)
about a.d. 110, a mere eighty years or so after the crucifixion of
Jesus, describing the official trials he was conducting to find and
The matter seems to me worthy of your consultation, especially on
account of the numbers of defendants. For many of every age, of every
social class, even of both sexes, are being called to trial and will
be called. Nor cities alone, but villages and even rural areas have
been invaded by the infection of this superstition. (Epistulae 10.96,
Pliny was in a rather distant and out-of-the-way province, and he
shows us that just a few generations after its beginning, Christianity
had 'invaded' every level of society. Another ninety years later,
around a.d. 200, Tertullian, a Roman lawyer turned Christian, in his
defiant open letter to the Roman magistrates defending Christianity
against persecution, could boast proudly that 'nearly all the citizens
of all the cities are Christians' (Apologeticus 37.8, gjr).
This last statement, we suspect, is something of an exaggeration made
for rhetorical effect, but both authors agree on at least two matters:
the number of Christians was considerable, even alarming."
Amazon.com: One Jesus, Many Christs (excerpt)
Search terms used:
"number of christians" + "first century"
"estimated" + "christians" + "first century"
"spread of christianity" + "first century"
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