Read Harts hope by Orson scott card it may give some Ideas about how to pull this part of your world off...
I would say please no to a world with one god....personally anyway...but hey I am a free thinking man
Ok I will tell you why I said read hearts hope in the terms you are looking for...
At one time three gods ruled the world the one whose name is simply God, The Great Hart, and the Sweat Sisters ( ok so they are a duality instead of one single goddess) Then the evil Queen Beauty who sacrifices her baby who was born in the 12th month of birth ( by sacrificing gains the level of a goddess due to blood payed magics) from an evil act of Good King Parcival Who then kills the other gods ( for in some freaky way she is at least a demigod if not a lesser god) and from their rules all the world ( or a least the kingdom of Parcival from the capital city of Burring.
To make along story short in her attempt to reak out punishment for the Good Kings one bad act she nearly destroys the world, Kills three gods, and keeps their spirits in limbo. Rulling all with her magical sight that hides in the clouds...
Its something similar to your Idea
