The following paragraph is my comment on a post by a person who blogs as The Dancing Professor.
I have thought about how I might help you in your search for the reasons early Christianity endured while other religions did not. These thoughts are not in any particular order since I have no idea how to weight them. They are: mutual sharing of resources, emphasis on the psychological and physical healing of individuals, a realistic view of the human condition, an ethics based on love of God and love of individual people, encouragement of fellow Christians to live up to the ethical standards of Christianity and display a high standard of behavior, support for individuals when they were facing mortal risk, an objective view of physical and cultural reality so as to understand them as neither ultimate or eternal, a hunger for wisdom that led many Christians into a search for truth, and an idea that there was at some level a unity of all Christians. I have not put forth any supernatural reasons for the continuance of Christianity although, of course, most Christians see the whole thing as an outpouring of the purposes of God mediated by the risen Christ and the Holy Spirit. Please let me know if this is helpful.
Frankly, I liked what I wrote and the religion it described. So I thought I would share it with the people who visit my blog.