This week I recalled how much I enjoyed all the courses in sociology that I took many years ago. I've been reading a study on how religious groups grow, split, innovate, etc. and the principles that operate, especially focused on Christianity ("The Rise of Christianity, How the Obscure, Marginal Jesus Movement Became the Dominant Religious Force in the Western World for Centuries").
The study separates sects (breakaways from existing groups) and cults (new religions). It seems to me that Christianity was a bit of both in the beginning anyway, although this is not suggested as far as I can tell in the reading. I see it as a part of Judaism with a new addition until after the destruction of the Temple in 70 CE and finally in 88 CE. Christians met in the synagogues with other Jews at first, telling their stories of Jesus as they related to the readings from the Torah, etc. that were the scriptures of that day. It morphed into a new religion beginning fully after 88 CE.
In the year 40 C.E. 0.00175% of the Greco-Roman World was Christian, in 239 CE it grew to 1.4% while by 315 CE it was around 17%. It grew slowly at first. Estimates say there were about 7,500 Christians by the year 100 for example.
The main growth in religious groups comes from relatives and friends and neighbors of converts and fans out in various directions from each new converted person. At first Christianity grew via Paul primarily in the artisan and fairly well off groups. As it moved out into the world, it became more Greek than Jewish in many ways. Some have suggested that Paul was a Plato kind of thinker.
What it means to be a Christian has changed dramatically over and over again. Even today, to say one is a Christian means widely divergent things depending on the group to which one adheres.
I've spent a great deal of time trying to understand the 1st century and what happened. And as a person fascinated by history, I watch in amazement as the streams spread out in a staggering array of beliefs, yet they all call themselves Christian.
We may never know all we want to know about beginnings and later meanderings through history, but we can do our best to discover and put the puzzle pieces together and then decide what seems to be the "truth" as best as we can discern it. And, we can be kind to those who followed a different stream and see from another vantage point. There is no way we can know it all.
Let us all do our best to be kinder and more open to explore the path - less authoritarian and dogmatic. What a difference that would make here on earth if we let go of hubris.
God bless us all.