In all Ancient cultures including ours the Idea of Age's Exist the numbers may vary but there has always been a categorization of the Ethical and Spiritual Decline of Human beings and the scaling back up
in Sat they where all Gods because Spirituality was perfected to a new Level and Material Technological dependency was Removed from day to day life and for grand endeavours
it is the power of Faith and less reliance on the technological Material Aspects
it was the same for Norse and Greeks perhaps even for other parts of the world
Polytheism was in essence to understand and Identify Various Attributes which match within a Human and in Nature
again it is the same Fractal patterns when you worship a aparticular God you are relating to his or her presence within yourself
Monotheistic religions are simply trying to Explain all the confusion which the mortal mind suffers in a simple Direct way
because people cannot grasp the complexities of faith and spirituality anymore
so to simplify faith a new set of rules is generated or commandments
but because the Human mind seeks answers which these path's cannot give Atheistic views gain Strength
the dogma or the fixed rules make it difficult to modify such views according to time and place
besides most such path's Sink down to Conquest and Slavery Eventually or from the get go and onset
In the modern age with technological advancement Political Ideas have taken over and people simply avoid Faith altogether
but without the Idea of Afterlife they do not fear Judgement for things which go Unnoticed by others
Still the Hunger to Believe and to make sense of things is even more so when Life is difficult in one manner or the other ,people end up following some kind of religion or Religious Leader searching for meaning to Life