Polytheism is belief in, or worship of, multiple and equal gods or divinities. The word comes from the Greek words poly+theoi, literally "many gods." Most ancient religions were polytheistic, holding to pantheons of traditional deities, often accumulated over centuries of cultural interchange and experience. Present-day polytheistic religions include Hellenismos, Shinto; some forms of Wicca; Vodun; and Asatru. Buddhism and Hinduism are regarded by some non-practitioners as polytheistic although this view of the religion is rejected by many believers. Some Jewish and Islamic scholars regard the Christian doctrine of the trinity as bordering on polytheism, a view that Christians in general strongly reject.

Ancient polytheism

Well-known polytheistic pantheons in history include the Sumerian gods; the Egyptian gods; the Norse Aesir and Vanir; the Yoruba Orisha; the Aztec gods; and many others. Today, most historical polytheistic religions are referred to as "mythology", though the stories cultures tell about their gods should be distinguished from their cultus or religious practice.

Few ancient religions, indeed, were not polytheistic. Those that weren't include early Vedic Hinduism (which has been termed at the most henotheistic with groundings of monotheistic, monotheistic and naturalist polytheistic philosophy), henotheistic Greek and Roman Classical Pantheon of gods, the Abrahamic religions, dualistic Zoroastrianism and Mithraism, and possibly the short-lived Atenism promulgated by Akhenaton in Egypt in the 1350s BC.

In many civilizations, pantheons tended to grow over time. Deities first worshipped as the patrons of cities or places came to be collected together as empires extended over larger territories. Conquests could lead to the subordination of the elder culture's pantheon to a newer one, as in the Greek Titanomachia, and possibly also the case of the Aesir and Vanir in the Norse mythos. Cultural exchange could lead to "the same" deity being renowned in two places under different names, as with the Greeks, Etruscans, and Romans; also to the introduction of elements of a "foreign" religion into a local cult, as with Egyptian Osiris worship brought to ancient Greece.

Gods and divinity

Henotheists come to regard their multiplicity of gods as representing aspects or facets of a greater divine unity: not a personal god as in the monotheistic religions, but an ultimate reality of the divine. Indeed, this monism extends even beyond monotheism in rendering the ultimate one formless and without attributs, the best known example being Brahman in Vedanta and Yoga streams of Hinduism. Modern Neopagan polytheists also often follow this model.

Although many forms of Buddhism include veneration of bodhisattvas, these are not regarded as divine entities. Rather bodhisattvas are considered to be human beings who have reached a high stage of enlightenment and one of the tenets of Buddhism is that over the course of many lifetimes, any human being can also reach a similar state of enlightenment.

That a person believes in multiple gods does not imply that he or she necessarily worships them all. Many polytheists believe in the existence of many gods, but worship only one. Max Mueller, however, spoke of a tendency to worship one being or principle, recognized as such, manifesting as many, and this particular theism was termed henotheism. Some people view henotheism as a form of monotheism, other as monism; some historians have argued that the monotheistic religions originated in henotheism. Practically all Jews, Christians and Muslims today, however, view henotheism as polytheism.

Idolatry

Polytheism is viewed by many monotheists as a form of idolatry. Monotheists argue that all power comes from one God alone, and not from any other supernatural entities, gods or agents. Even if some polytheists espoused the view of one greater lord above other gods, it implied ideas that the supreme god was somehow limited by the presence of separate god-entities, and thus though more powerful, was more like a king among men than a limitless potentate. As monotheists believed in only one God (examples being Allah, Yahweh, etc.) they generally considered it sinful to endorse polytheism.