How did polytheism begin?

Answer 1

Polytheism began thousands of years ago, and it is not known exactly when or how. Early people used many gods to explain things that happened in nature.

Answer:

Based upon a massive worldwide study of the most ancient inscriptions and the earliest levels of civilization, Dr. Wilhelm Schmidt (in his twelve-volume Der Ursprung Der Gottesidee) concluded that the original belief was monotheistic1. It was a simple belief in the Creator (Sky-Father) with no imagery of any kind. It gave way relatively quickly to polytheism and idolatry, but its traces could still be seen by the careful researcher, just as (for example) Proto-Indo European has left indelible marks within the later languages. Other traditions also are traceable worldwide, such as the religious significance of the number seven, and the immortality of the soul.
The process by which the awareness of One God gave way to a belief in many gods, has been described by Scandinavian researchers2 as splitting ("Gottespaltung"): the people gradually viewed God's attributes of truth, righteousness, fertility etc., as separate from Him, and afterwards personified and worshiped the attributes themselves, until God was largely forgotten.
Maimonides3 describes a comparable process (which probably happened alongside the aforementioned one), as follows:
A couple of centuries after the Creation, mankind made a great mistake: They said that since God had created the stars and spheres and placed them on high, accordingly it is fitting for people to praise and glorify them and to treat them with honor. They perceived this to be the will of God, that people should magnify and honor the stars. They began to praise and glorify them with words, and prostrate themselves before them, because by doing so, they would - according to their false conception - be indirectly honoring God too.

Notes: 1) Albright, "From the Stone Age," p.170; and J.A. Wilson, "The Culture of ancient Egypt," p.129.
Also Baron, "A Social and Religious History," vol. I, p.44 and 311.
Also James Meek, "Hebrew Origins," p.188, quoting Langdon, Lagrange and John Ross.
Also Martin Nilsson, Handbuch der Altertumswissenschaften, 2nd ed., p.61, 141, 220 and 394.
2) G. W. Anderson, in "The Old Testament and Modern Study," p.287.
Also Friedrich Baethgen, in Beitraege zur Semitischen Religionsgeschichte, p.288.
Also Pallotino, "The Etruscans," p. 158 and 167.
3) Maimonides' Mishneh Torah (Hilchot Avodat Kochavim ch.1).