There are many methods of interpretation. The bottom line is this--can and does God speak so that any normal person will understand it? With the allegorical method, for instant, you would need a fistful of doctorates to interpret. Why would God speak in a hidden understanding? Even with prophetic passages the best interpretation is to take the words in their plain, normal sense. We don't understand the meaning? So? The time will come when prophesy is being fulfilled that the people will understand. See 1 Peter 1:12.
Here is a good article on Bible Interpretation by Cooper P Abrams III--Principles of the Literal Bible Interpretation.