Polytheism (from the Greek words polus and theos, literally “many gods”) is simply the view that there are multiple deities. Polytheism has to be classified as a Finite Theist worldview because if there are many gods, they have to be finite and limited in power. (Think it through: there can’t be multiple all-powerful beings because each one would have the power to defeat every other one, in which case they wouldn’t be all-powerful after all.)
Polytheists typically believe that the gods exist within the natural universe rather than transcending it. That helps to explain why the gods are limited: they’re constrained by the natural laws of the universe.
The ancient Greeks and Romans held to this form of Polytheism, as did many other ancient cultures. It’s less well known that Mormonism also represents a Polytheist worldview. According to the traditional teachings of the Church of Jesus Christ of Latter-day Saints, there are many gods, and those gods were once human beings. As one Mormon apostle, John A. Widtsoe, famously put it, “Man is a god in embryo.”45 So gods are nothing less than exalted human beings. But since humans are physical beings, so are the gods. They’re limited by the basic physical laws of the universe, just as we are.
Polytheism has cropped up many times in the history of mankind, but it isn’t a very philosophically satisfying worldview because it has no good answers to some very basic questions. Where did the gods come from? Where did the universe come from, and why does it have the laws it has if the gods didn’t create it? (Remember that Polytheists typically believe that the gods are part of the universe—they exist within it—so they can’t have created it.)
Another problem for Polytheism is connected to your answer to the Goodness Question. You said that some things are objectively good or bad, which implies that there is an ultimate standard of goodness. Where does it come from?
For the Monotheist, who believes in one absolute and infinite God, it’s obvious that God must be the ultimate standard of goodness. One God, one ultimate standard. No problem!
But the Polytheist faces an awkward question at this point: Which God? If there are multiple gods, doesn’t that mean there are multiple standards of goodness? If so, it looks as if the Polytheist must settle for relativism or arbitrariness when it comes to the ultimate standard. (“Pick a god, any god!”) There’s also the tricky question of which god to worship and obey.
Of course, the Polytheist may prefer to say that no god is the ultimate standard of goodness. Rather, the ultimate standard of goodness is distinct from all the gods and transcends them. But in that case, wouldn’t that ultimate standard be the Supreme Being, since it transcends the gods and stands over them? It seems the Polytheist has to deny that there’s any ultimate standard or he isn’t really a Polytheist after all.
(from James Anderson's "What is Your Worldview?")