Sage Sankara’s Supreme Brahman is impersonal, Nirguna (without Gunas or attributes), Nirakara (formless).+

God in truth is not something that is easy to realize. God in truth can be realized only when you realize the Self is not you but the Soul, which is present in the form of consciousness. 

God is universal because God is impersonal. God does not belong to any religion because religious Gods are personal.

How can you see God without knowing what God is in actuality?  When the ‘Self is not you how can you find God within you? God is not within you. Those who say God is within you just propagating half-baked knowledge.

Sage Sankara’s Supreme Brahman is impersonal, Nirguna (without Gunas or attributes), Nirakara (formless), Nirvisesha (without special characteristics), immutable, eternal, and Akarta (non-agent). It is above all needs and desires. It is always the Witnessing Subject. It can never become an object as It is beyond the reach of the senses. Brahman is non-dual, one without a second. It has no other besides it. It is destitute of difference, either external or internal. Brahman cannot be described because description implies a distinction.  Brahman cannot be distinguished from any other than It. In Brahman, there is no distinction between substance and attribute. Sat-Chit-Ananda constitutes the very essence or Svarupa of Brahman, and not just Its attributes. The Nirguna Brahman of Sage  Sankara is impersonal. 

Rig Veda:~ Prajnanam Brahma: - Consciousness is the ultimate reality or Brahman or God in truth.

Bhagavad Gita says: ~ Brahmano hi pratisthaham ~ Brahman (God in truth) is considered the all-pervading consciousness, which is the basis of all the animate and inanimate entities and material. (14.27).

There are neither Gods nor Goddesses but only consciousness. Consciousness is the ultimate truth or Brahman or God in truth. 

Consciousness is God in truth. All Gods based on blind belief are not God in truth.

Rest in consciousness by realizing the world in which you exist is nothing but consciousness.

The truth is very simple. It is only to realize the world in which we exist is created out of single stuff. Knowledge of a single stuff is Self-knowledge. Self-knowledge frees us all from ignorance.

We have to discard all accumulated knowledge accumulated from different Gurus and teachers.

That is why Sage Sankara says:~VC-65- As a treasure hidden underground requires (for its extraction) competent instruction, excavation, the removal of stones and other such things lying above it, and (finally) grasping, but never comes out by being (merely) called out by name, so the transparent truth of the Self, which is hidden by Maya and its effects, is to be attained through the instructions of a knower of Brahman, followed by reflection, meditation and so forth, but not through perverted arguments.:~Santthosh Kumaar