Christianity helped the development of earliest states in Russia, because:
1) It gave the Russian people something to unite with
-As russia was made up of different people groups, they only united if they have similarities, which, in this case, was Russian Orthodox
2) It gave them a then-powerful Byzantine Empire as an Allie
- Because they share religion, they became allies. This allowed them to trade with each other, and to help each other (at least while the Byzantine Empire lasted)
hope this helps