Oh, if only literature were so simple!
Not even English literature always provides an introduction to something symbolic. For an offbeat illustration Ayn Rand stated that there was symbolic language in the novel [u]Atlas Shrugged[/] – and that she felt no obligation to point out what was symbolic because she assumed her readers possess basic intelligence. Indeed it isn’t all that uncommon for writers to deliberately not provide any indication at all that they’re shifting to symbolic language because the nature of the story requires that the reader figure it out for himself/herself! It’s also not uncommon to write in a way that could be read literally or symbolically – and sometimes is meant to be taken both ways – and each works for the story. That gets done in poetry, too; as a high school freshman I won in a national poetry contest with a poem that my teacher thought could be read three different ways, one literal, one with metaphors, and one totally symbolically, and I’m far from a good enough poet to do that regularly, but real poets do it all the time.
Heck, one of the most common debate topics in my college literature courses was whether a piece of writing was meant literally or symbolically, or mixed, or both!
From the New Testament canon we have a superb example of symbolic language with no “introductory language”, yet the readers knew right off that it was symbolism all the way through – and that brings me to the critical point here: people in a given culture don’t need to be told that something is symbolic most of the time because they recognize the genre of the literature; that’s why John didn’t have to say, “Okay, I’m using symbolism now”, his audience would recognize the literary genre and just know that.
Ancient Hebrew writers did all those same things I’ve described, expecting the audience to recognize when something was symbolic. How did the audience know? Because they recognized the genre of the story.
But we don’t have that advantage; we have to do our homework to even know what genres they had. For a long time it was common to read the first Creation account literally because no one knew what genre it actually was, so they read it as being in a genre they knew. But God has privileged us to learn enough that we can try, as Dr. Michael Heiser puts it, to “have an ancient Israelite living in your head”, and even if we are very good at that we come much closer to the richness of the message of the scriptures than if we didn’t even try.
And if we don’t try, that shows we have no respect for the original audience, nor for the writer, nor for the Holy Spirit who inspired that writer.