I'm still enjoying Ben Witherington's commentary on Acts.
Here's a great insight into early Christianity's advantage over the established religions of the ancient world. Sure we live in a different world today.
Christianity arose during a time when there was already enormous religious curiosity on the part of Romans and other pagans about Eastern religions and divinities ranging from Isis to Jesus. It sought to take advantage of this curiosity, and it offered to pagans a religion that did not require certain rituals (such as circumcision or the keeping of food laws) that would have immediately alienated them in obvious observable ways from their fellow Gentiles.
It did not require temples, costly animal sacrifices, priests—the very essence of much of ancient religion. It could meet in homes, and its rituals were flexible.
It is not surprising that in the course of the next two centuries it came to be seen by pagans as a much more appealing religious option than Judaism, ordinary magic, or various other forms of traditional and popular religion that existed in the Empire. The irony of course is that when Christianity was finally endorsed by the Roman emperor it was well on the way to taking on the very properties of other ancient religions with priests, temples, sacrifices, and the like. One must ask, then, whether in the end Christianity was more the bearer or recipient of socialization in the Empire.
Yet the principle stands. If you want it to multiply and adapt—keep it simple.