As the ancestors of the Greeks, with the Aryans of India, the Egyptians, and others advanced in civilization, their religious thought was shocked and surprised by myths (originally dating from the period of savagery, and natural in that period) which were preserved down to the time of Pausanias by local priesthoods, or which were stereotyped in the ancient poems of Hesiod and Homer, or in the Brahmanas and Vedas of India, or were retained in the popular religion of Egypt.
At the same time he wisely strove to gain the goodwill of the powerful priesthoods of the great sanctuaries of Delphi and Olympia.
And from the social side the development of law, the influence of city life, the formation of priesthoods, the connexion of particular deities with the fortunes of dynasties or the vicissitudes of nations, the processes of migration, of conquest and political fusion, the deportations of vanquished peoples, even the sale of slaves to distant lands and the growth of trade and travel, all contribute to the processes which expand and modify different pantheons, and determine the importance of particular deities.
The formation of clans and tribes, the transitions from the hunting to the pastoral life, and from the pastoral to the agricultural - the struggle with forest and swamp, the clearings for settlement, the protection of the dwelling-place, the safety of flocks and herds, the production of corn, - the migration of peoples, the founding of colonies, the processes of conquest, fusion, and political union - have all reacted on the elaboration of the higher polytheisms, before bards and poets, priesthoods and theological speculators, began to systematize and regulate the relations of the gods.
Akhenatons reform had not reached deep amongst the masses of the population; they probably retained all their old religious customs and superstitions, while the priesthoods throughout the country must have been fiercely opposed to the heretics work, even if silenced during his lifetime by force and bribes.