When you reduce everything as consciousness then there is nothing exists there is only Advaita.+

Sage Sankara said:~ Talk as much philosophy as you like, worship as many gods as you please, observe ceremonies and sing devotional hymns, but liberation will never come, even after a hundred aeons, without realizing the Oneness.

Only through deeper self-search do beginners and intermediates gradually become aware ‘what is what’. Only after they have realized the fact that the ‘Self’ is not ‘I’ but the ‘Self’ is the Soul, which is present in the form of the consciousness,  they are ready for the inner journey towards reality, which is beyond the form, time, and space.

Upanishad: ~ “They alone in this world are endowed with the highest wisdom who are firm in their conviction of the sameness and birthlessness of Atman. The ordinary man does not understand their way. (Chapter IV — Alatasanti Prakarana 95-P-188 in Upanishads by Nikilanada)

If you are seeking truth you have to know the ‘Self’ is not you but the ‘Self’ is the Soul, which is present in the form of consciousness.

Sage Sankara says:~  you must first know what is before you. If you cannot know that, what else can you know or understand? If you give up the external world in your inquiry, you cannot get the whole truth. 

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.

People refuse to accept anything other than their Gurus words. For them, their Gurus words are the ultimate truth. They do not accept anything else other than their accepted truth. There is no need to convince such a mindset.

Such mindsets are not fit to acquire Self-knowledge or Brahma Gnana or Atma Gnana. The seekers of truth accept only the truth nothing but the uncontradictable truth.

First Mundaka - Chapter 2 (8):~  Fools, dwelling in darkness, but wise in their own conceit and puffed up with vain scholarship, wander about, being afflicted by many ills, like blind men led by the blind.

Mentally reduce the universe as the consciousness by realizing the universe is nothing but an illusion created out of consciousness.

Mentally reduce the three states as the consciousness by realizing the three states is nothing but an illusion created out of consciousness.

Mentally reduce the form, time, and space as the consciousness by realizing the form, time and space are nothing, but an illusion created out of consciousness.

Mentally reduce your body, ego, and the world, in which you exist as the consciousness by realizing your body, ego, and the world, in which you exist is nothing but an illusion created out of the consciousness. 

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

When you reduce everything as consciousness then there is nothing that exists other than the Advaita. The nature of the consciousness is Advaita.:~Santthosh Kumaar