@Jennifer:
After the Roman Empire(s) fell, the church maintained the religion and practice which may have stymied independant developments of languages a little. At least until writters began writting the Bible in native tongues.
I don’t think that the language of the “intellectuals” had too much influence on the people. Remember, that even many low-level priests were not able to speak latin and thus to understand what they actually “preached”.
Also, you should check when the bible was translated into native tongues. Greek is a native tongue and the language of earlier bible versions. There was a gothic version, even during the last west roman days.
I think you make the mistake of first saying “all christianity is latin”, and of overestimating the influence of a very few in a very feudal and class-aware society like it was in the Dark Ages.