If I understand this correctly, then it seems to me that any overlapping that occurs between the works only ties them together and is not a bad thing.
As for the side characters who are not seeking inspiration from scripture or sacred music, since you have secular tunes in the mix, it is in...
fusty- something old-fashioned and out-of-date.
Sadly, those that cling to the notion that traits like politeness and patience are good are largely perceived as oh so fusty.