Strict emphasis on division would ultimately render it impossible for you to read anything but a very recent book produced by someone in your area sharing your ethnic background and religious beliefs. True, a few people do want to peruse only such materials, but these are hardly lovers of literature. C. S. Lewis in An Experiment in Criticism puts the emphasis on the response of the reader. To read in a literary way is based on wanting the book to be itself, and entails the reader's strong desire to return to it, and to reread it. The delighted re-reading involves an attention to the words and images, and to a feeling that goes with them that the reader wants to recapture.
Literature is what the true reader finds it to be.
That does not mean there are no good ways of reading, or that some help, even training, in ways of reading cannot help the reader create a more complex experience. V ery well, then. That is perhaps the tougher nut to crack. In any period, such ideas and images, even the most intensely nationalistic, float across boundaries, and are transmitted in a variety of ways. If we go back to the ancient world, we may and probably should do so refreshed and stimulated by modern knowledge and approaches.