Personally I don't have a lot of experience as a GM, but I'm sure you'll be able to recruit someone around here. Lots of RP'ers.
Anyway, about the ideas...those were just two I thought of off the top of my head. The priest was taken from the idea of the Law of Moses being too much for the Pharisees and such of the old testament; it was to prove that man alone is sinful by nature, and thus cannot honestly fulfill every single one. Perhaps a character in your RP could follow a very strict, but complex and demanding 'god' and face the same issues. Whether you have him "rescued" to the true God or not is dependent upon how Salvational you want this thing to be.
The prophet without an audience was taken from the passage in the Gospels reading "a prophet is without honor in his hometown." Basically, no one believed Christ was the messiah until after he had risen from the dead (there are a few exceptions, granted, but I'm speaking generally here); similarily, in today's society people shrug off Christians as 'religious' for the most part and try not to get too caught up with them. No one heeds the warnings by us 'prophets' telling them they will die if they don't turn. I was thinking a Cassandra type figure, or even John the Baptist gone fantasy, something like that. The bible is riddled with other examples you could throw in there for good measure; the story of Ruth, for example. These stories illustrate a Christian theme without being...well, blatant about it.