Sage Sankara was criticized for his views on Maya (illusion) without understanding him.+

Sage Sankara: ~ “VC~ All this universe which through ignorance appears as of diverse forms, is nothing else but Brahman (Consciousness) which is absolutely free from all the limitations of human thought.

When you finally realize the ‘‘Self’ ‘is not you but the ‘‘Self’’ is the Soul then you will realize the world in which you exist is merely an illusion created out of the Soul. The Soul is present in the form of consciousness.

Sage Sankara says:~VC-47 All the effects of ignorance, root, and branch, is burnt down by the fire of knowledge, which arises from discrimination between these two—the Self and the non-Self.

Until you think you are an individual separate from the world and the world existed prior to you and you are born in it afterward the ignorance will prevail as a reality. Till ignorance is there the universe prevails as reality. 

Till you realize the whole universe an illusion you will not be able to realize ‘Self’ hidden by the universe.

In fact, Sage Sankara states a paradox- the world is and is not. It is neither real nor unreal. It leads us to recognize the existence of Maya (illusion). He thinks that the world is illusory from one perspective and from the second it is nothing but Brahman(God), Itself in manifestation. This apparent world is Maya and has its basis in Brahman, the Eternal. It looks as real. It has names and forms and actually, it is not real In the light of true knowledge, it disappears and Self-alone shines as real. However, Sage Sankara's Mayavada has not been accepted by many preachers and philosophers.

When Sage  Sankara says clearly, that the universe is not real. He says that Brahman and Atman are one. The ultimate and the Absolute Truth is the Self, which is one though appearing as many in different individuals. The individual has no reality. Only the Soul, the innermost  Self is Real; the rest, mental and physical are but passing appearances, then it indicates the form (waking or duality or mind) is unreal and the formless soul (consciousness or soul) is real.  Therefore, only Atman is real because there is no second thing exists other than Atman, which is in the form of consciousness.

Remember:~:

Sage Sankara was criticized for his views on Maya (illusion) without understanding him. He said: ~ 

(1) Brahman (Atman) is real.

 (2) The universe is unreal.

(3) Brahman is the universe.

He did not stop at second because the third explains the other two. It signifies that the universe is real if perceived as the ‘Self’ and unreal if perceived as apart from the Self. Hence, Maya or illusion and reality are one and the same. 

The realists criticize the concept of illusion without understanding it. He said: ~

(1) Consciousness (Atman) is real

(2) The universe or mind is unreal, and

(3) Consciousness is the mind or universe because the universe or mind is merely an illusion created out of consciousness.  

One need not stop at second because the third explains the other two. It signifies that the universe is real if perceived as the Self (Atman or consciousness) and unreal if perceived as apart from the Self (consciousness). Hence, illusion and reality are one and the same because both are one in essence. Realizing the essence, which is consciousness as the innermost Self, is Self-Realization or Truth-Realization of GOD- Realization. Thus Sage Sankara‘s declaration is the rational truth, scientific truth, and also the ultimate truth.

The ultimate truth or Brahman (God) dwells within the three states like fragrance in the flower; Musk lies within the Musk-deer yet seeks it afar." Until one trace the truth within the three states the illusion of birth, life, death, and the world is experienced as reality. 

The world is both real and unreal. It is real because it is a manifestation of consciousness, but is unreal, in the sense, that it is not absolute and eternal like consciousness itself.

People's approach is more practical, and they stuck with the reality of the world, they take it as real. That is why all the confusion.

That is why Sage Sankara says: ~ VC-63. Without causing the objective universe to vanish and without knowing the truth of the Self, how is one to achieve Liberation by the mere utterance of the word Brahman? — It would result merely in an effort of speech.

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.

All the penances are external because they are based on individuality. Investigating the mind, alone leads to self-realization. To know what is the mind, profits much rather than searching for the truth in the external world moving from one ashram to another and one guru to another, and one mountain to another. When one starts investigating the universe that confronts him will mentally move inwards and will reach the ultimate end and become fully aware “What is the truth?” and “What is untruth?” in his own home or city and establish in truth by realizing what is the untruth.:~Santthosh Kumaar