What confuses people is that they have this overly eurocentric idea that monotheism and polytheism are strictly divided things, when this has never been so. What most westerners label polytheism is usually a sort of hierarchical monotheism, pantheism, or polyentheism. The multiple gods are part of a whole or manifestations of it. There has always been the principle of one-ness. The problem was that politicians wanted people to elevate a specific being or concept to the place of "highest" in a psychologically conflicted way. Instead of merging all forces of Nature and spirits into one being, they took one of the "baser" aspects or manifestations and propped it up for their interest. Monotheism in that sense is not an advancement or evolution of spirituality, but a degradation of it. It happens in steps...people have a belief in a universe that makes sense, and then they become more urbanized and gradually twist it into a universe where gods have quid pro quo, and then eventually, there's a single god the leaders claim has their back and the right to override all others.