You have a clear writing style thus you turn complicate concepts into understandable pieces.
Monotheism and God as a personification are just a late inventions, originally animistic religions were wildly spread. Most of the time deities personify some atributs or ideas like Athena- knowledge. It is easier to grasp things in this sort of way by turning abstract into more tangible.
However I do not agree that God is no longer needed. I do think that in these times we need it most. We need something to personify higher values and standards that inspire and guide. A shift into what God represents instead of an annihilation would be more suitable.