Full Idea
In Hegel the essence of God is actually nothing other than the essence of thought, or thought abstracted from the ego, that is, from the one who thinks.
Gist of Idea
God is the essence of thought, abstracted from the thinker
Source
report of Georg W.F.Hegel (Phenomenology of Spirit [1807]) by Ludwig Feuerbach - Principles of Philosophy of the Future §23
Book Reference
Feuerbach,Ludwig: 'Principles of the Philosophy of the Future', ed/tr. Vogel,M [Hackett 1986], p.36
A Reaction
Presumably Descartes' Cogito is the origin for this train of thought. This is Feuerbach's reading of Hegel, but the former was keen on the idea of God as idealised humanity.