Heh, funny you'd mention that, as the longstanding claim has been that the story was an allegory of the Populist party of Baum's day, even taught as such. HOWEVER, simply because a story lends itself to an allegorical interpretation does NOT mean the author INTENDED it to serve as a particular allegory. Being that you're willing to live your life based on allegories of the Bible, you'd be wise to study the subject of literary criticism, perhaps starting with Baum's "The Wizard of Oz".
I am well aware that writers put allegory into their stories for various purposes not always known (like an easter egg) However, the Wizard of Oz is a very special movie from a very special time, not to mention bringing color film into the mainstream. The books I am not terribly familiar with. Have you heard Oprah's interpretation of the Wizard of Oz film? She's a wise woman. "You always had the power" is very reminiscent of eastern thought which has greatly influenced western thought. It's eternally special.
-Sab