The succession pattern in the Theogony, a sky god deposed by his son, that son overthrown by a storm god after swallowing a stone, is not a Greek invention. The Hittite archives at Hattusa yielded the Kumarbi cycle, a group of texts of Hurrian origin surviving in Hittite versions from the second millennium BCE, in which Kumarbi bites off the genitals of the sky god Anu, becomes pregnant with the storm god Teshub, and is eventually displaced by him, with a stone monster named Ullikummi featuring in the struggle. The Babylonian Enuma Elish offers a related shape, generations of gods in conflict resolved when a younger god defeats a primeval opponent and is acclaimed king. The correspondences are close enough that most scholars accept transmission from the Near East into Greek tradition, plausibly through north Syria and Cyprus in the centuries before Hesiod, rather than independent invention.
The poem's own standing in Greek religion is easily overstated. Greeks had no revealed text, no creed and no body empowered to define doctrine; worship consisted of sacrifice, festival and observance, and belief was not policed. Herodotus wrote that Hesiod and Homer were the ones who made a divine genealogy for the Greeks and gave the gods their epithets, honours and forms. He was describing cultural influence, not canonisation, and he says in the same passage that this was his own opinion. Local cult often contradicted the poets, and no one was troubled. The Theogony was authoritative in the way a standard reference is authoritative, not in the way scripture is.