1: because of its Jewish monotheism it was universal in scope.
2: in looking to a god-human in Jesus it presented a theme very familiar to the graeco-roman world
3: it was able to pick up themes from the platonic tradition which would make the faith appealing to the educated person
4: the nature of mystery, a sacred meal, was more in the way of commitment to beliefs than the other cults
5: periodic persecution reinforced the solidarity of the group
6: empty formalism of the emperor cult and the marked pluralism among the elite pointed the lack of coherent state ideologie.
7: consistent organization, system of bishops
8: able to fight of its pessimistic Gnostic rivals