The real selling point about Christianity in its early days
Was that just about ANYBODY could be a member. Most other religions
were essentially secret societies and you had to be specially chosen
(or know whose butt to kiss) to be allowed in (like a country club, only
without the golfing).
But with Christianity, anyone could join no matter what your social rank
or even if you were a "sinner" - in fact, sinners were their specialty,
as Jesus said he did not come to heal the well but the sick.
Of course most Christian groups are still quite good at letting most folks
in, but the fees and penalties have gotten a lot stiffer. But at one time
the fledgling cult did offer hope to people in a world where there was
often little or none.