I think Lucy24 had a good point about noindexing, and here's an additional thought. Build a page that discusses a particular text, and design it to rank for the text's name or whatever searchers are likely to use. On this page you could talk about the historical context, any interpretive issues, etc. Then it could link to a no-indexed page containing the actual text. That way, you have a page that can rank for the phrases you're targeting AND lead visitors to the text, but you're not relying on "dupe" religious texts themselves to rank.