There are quite a number of theories and perspectives on how in just three centuries Christianity grew from a small (20-30) group of peasants, to about 3,000 at the end of the first century, to convert almost all of the huge Roman Empire by the end of the fourth century. Of course the big turning point was Constantine's help in the 300's, but there were also other factors.
One perspective is focused on how different paganism was from Christianity. Pagans were inclusive, the more gods the merrier. Christians were exclusive, to join you have to let go of pagan gods. There is no evidence for pagan evangelism. Christians were constantly sharing their teaching, heavily weighted with apocalyptic zeal - the world was going to end soon and people were not risking annihilation but eternal torture. Pagans had ethics, but not because of their religion, but rather because of philosophy and cultural norms. Christian teaching was ethical in many ways, especially the mandate to love everyone and to live as Jesus lived.
One example of Christian love was dramatically shown during epidemics. Pagans were afraid of catching the disease and often threw the sick out on the streets. They had a high mortality rate. Christians tended to the sick and had a low mortality rate. This got people's attention.
History shows Christianity spread primarily by word of mouth. Each person shared with their circle of friends, family and acquaintances. And on and on it went.
Interestingly, Paul kicked it off as the first missionary. The whole concept of evangelism was strange to the people of the day. No other known religious group actively worked for converts. In fact, there are only a few named missionaries in the first four centuries: Gregory the Wonderworker, Martin of Tours, and Porphyry! This supports the current understanding that word of mouth was key.
So we come to today with a decline rather than growth. We come to a time when many are hesitant to share spiritual thoughts. We come to a time when people are busily engaged in other things and often don't have deep, personal experience of God.
I keep pondering how we can turn this around. With my spiritual life so essential to me, I wonder how can I help others to find that precious connection? This blog is one tiny way I try to encourage thinking and spiritual growth. I hope you share in your own way how wonderful it is to be Awake and Aware in The Presence of God.