Anyone with reading skills can try to figure out for himself what the author of a book is saying. But, because of the "limits of language" -TD, if one really wants to know for sure, only the author knows exactly what he means and only the author can explain what he means. When it comes to legislation, Courts are authorized to interpret the law and to apply cases to the law because Courts (Judges, juries, etc.) are authorized to do so by the authors of such laws and by other authorities that govern and decide how written laws should be interpreted and by whom.
Given that the Bible is "God's Word," one can only know what the Bible teaches by asking God. Surely, if the Bible is in fact a book authored by God, it is logical that if He would want it understood, HE would somehow communicate with anyone that truly wanted to understand it. Any claim of authority to interpret the BIble must be verified by its author and only with such evidence could one really know and personally conclude who is authorized to interpret the Bible. The problem with conclusions is that when they are based upon false logic or erroneous thinking ;or the delusion of confusing evidence with a derivative from the evidence (something that cofty does a lot) such conclusions are not right. MY advice to you is not to trust the conclusions and assertions of others as truth. Investigate for yourself. IT ain't easy, but only you can detemine for yourself what is real or what is a sham.