God is the soul of soul. Because it is only through him we get all the energy that we need to do the work, to think, to see, to smell, to hear and so on.
The fundamental difference between devotion and non-dualism
There is fundamental difference between these two disciplines. Adwaita or non-dualism lacks the beauty of love. Love needs Lover, Beloved, Love itself and Relationship (Father, mother, sister, husband and so on). Non-dualism takes a view that there are no two personalities existing, everything is I. There is no difference between God and I. Because of such view, possibility of developing love does not exist. The devotion, on the other hand, allows love to develop by allowing lover and beloved relationship between God and Soul.