The seeker has to investigate on his own and realize the ultimate truth or Brahman

Deeper self-search reveals the fact that the true Advaita expounded by Sri Sankara and his param guru, Goudpada is pure Self-knowledge or Brahma Gnana or Atman Gnana leads one to Self-awareness whereas the orthodoxy more concerned with the practical life within the practical world indulging in non-Vedic rituals.

Sri, Sankara says in Brahma Sutras: that Brahman is the cause of the world, whereas in Mandukya he denies it. This is because he says that at the lower stage of understanding, the former teaching must be given, for people will get frightened as they cannot understand how the world can be without a cause, but to those in a higher stage, the truth of non-causality can be revealed.

Sri, Sankara himself has warned us not to use ambiguous words, and to practice semantic analysis in his book "Definition of one's own Self. [" Page 199, v.24 of "Sankara's Selected Works]

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

Sri, Sankara’s notion of Maya, the cosmic illusion [mind or matter], which must be transcended in order to realize the truth of Brahman, which means ultimate truth. 

If Brahman is considered the all-pervading consciousness then, it is necessary to realize, the consciousness as self, which pervades all the three states, to realize the fact that, there is no second thing exists other the consciousness. Thus, consciousness [Ataman] is ultimate truth [Brahman].

The Sruti itself says: "This Atma is NOT to be attained by a study of the Vedas. [Katha Upanishad I, 2, 23.]

It means the seeker has to investigate on his own and realize the ultimate truth or Brahman.-FORMLESS PATH