A big chunk of Stanley Wolpert's India is devoted to Hindu theology. It's suitably baffling in its complexity. Regular readers may recall that I like to try to find the evolutionary rationale for religions. In some cases, it seems relatively easy, but India is surely a special case.
Of course I don't understand much, but in many ways the Hindu gods seem to me to bear a resemblance to the kinds of gods found in the early polytheistic religions of Europe and the Middle East. They are embedded, however, in a higher level religious and cultural philosophy that seems to underlie and unify the whole culture.
I probably shouldn't spend to much effort on this complex task, but I suspect my odds of understanding India without it are poor.