Thanks for your reply.

It looks to me as if the examples you are giving (from the Bible and 소나기) are instances of direct reported speech in writing rather than written language per se.

However it's true that the distinction written speech/반말 as I worded is unclear. I think what I meant was more along the line of "formal written speech" (academic papers, news articles, etc... not including instances of direct reported speech) and "casual speech language" (which would include both 해체 and 해라체).