Millenia ago when human minds were much more 'primitive,' so to speak, they may have imagined that things that occur naturally, such as Thunder, Lightning, Earthquakes and the like MUST be the result of something Immensely Powerful, etc, etc, that controlled all things, hence they may well have developed the God/s/Goddesses to compensate for their lack of understanding things so natural.
It may well be worth mention here that OF the Divine Entities dreamed up by Humans ONLY those from Ancient Egypt were NOT classed as God/Goddesses but as being Elemental Forces and represented ONLY as hybrid human-animal figures.
The classification of these Ancient Egyptian Elementals came about when Champollion was de-cyphering the Rosetta Stone and the Vatican ORDER him, on pain of Excommunication, to definite the Elementals as Gods, etc, so as NOT to undo/destroy the Ideologies upon which the Christian God was based as being a Humanoid Being and a Supreme, Omnipotent, etc, etc, Divine Entity and the One and Only True God.