You now think that you are an individual, there is the universe and that God is beyond the cosmos. So there is the idea of separateness. This idea must go. For God is not separate from you or the cosmos.
The Bhagavad Gita also says:
The Self am I, O Lord of Sleep,
In every creature’s heart enshrined.
The rise and noon of every form,
I am its final doom as well. (BG, X:20)
Thus God is not only in the heart of all, He is the prop of all, He is the source of all, their abiding place and their end. All proceed from Him, have their stay in Him, and finally resolve into Him. Therefore He is not separate.
(Source: Talks with Sri Ramana Maharshi, Talk 649)