A great majority of Hindus are not in contact with their religious history therefore, they believe their inherited beliefs as ultimate truth.+

Sage Sankara’s Supreme Brahman (God in truth) 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 the description implies a distinction. Brahman cannot be distinguished from any other than It. In Brahman, there is not a 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.

The Puranas:~

The PURANAS, including Vishnu Purana and Siva Puranas, are based on the false idea of a personal God because the writers have thought of Him as a glorified man and woman.

The translations made till now of Indian philosophical works have represented religion and mythology, not philosophy. The greatest pundits do not understand it, for they do not understand science. What has this mythological teaching done for India? Look at its state today. Look at the conversions. Imagining that God has ashes on his forehead or blazing like the sun-- that is all poetry and depends only on faith.

The Saiva Siddhanta sect is a dualistic, unphilosophical religion like Ramanujan’s sect.

Why did not Ramanuja and Madhva write commentaries on the Upanishads (as Sankara did to establish Brahman) but stop, content with writing the commentary on Vyas Sutras, and culling some paras only from the Upanishads with convenient vagueness to establish their God and Theology?

Indians are more religious than other people. The six systems of Indian Philosophy are really six systems of Indian speculation. For there is only one Truth.

The ancient Hindu tenet borrowed by theosophists of the universe appearing and dissolving, days and nights of Brahma, entering into pralaya, etc. is intended for mediocre intellects who cannot rise to the truth. It is a convenient fable representing the philosophic truth that the whole universe dissolves in your mind in deep sleep, thus entering pralaya, and rises again the next morning, i.e. it is all imagination, idea. The Brahma or God in truth has nothing to do with it. 

As we peep into the annals of the religious history of India:~

A great majority of Hindus are not in contact with their religious history therefore, they believe their inherited beliefs as the ultimate truth.

Hinduism is based on myths and thus, the people of India are unaware of the facts of their inherited religious history. The Vedic Culture and Vedas are complete in themselves but Hinduism which is a non-Vedic belief system with all its ritual and conduct-oriented practices has been contributed largely by the orthodox priests to suit their convenience!

Vedas are in the Vedic language which was a high-class language. Rig Veda (excluding chapters II and X) was written before the Christian Era in Vedic language.  Vedic language is not Sanskrit.  It is the same language in which the Zoroastrian Scripture Zend Avesta is written – a form of Persian language.  All the other scriptures of India are written in Sanskrit.  

These include Rig Veda Chapters II and X and the Upanishads, Brahmanas, Puranas, and the Vedanta.  These were written during the Christian Era after the Thomas ministry. As the use of this language diminished, it became a tough language for the commoners. The priests, who were supposed to be experts in this language, translated it into Sanskrit language and manipulated the meanings in time and gradually, all the practices changed.

The DaVita, Vedanta borrows the concept from Abrahamic religions, such as Eternal Damanation (of certain Souls destined to hell forever) which goes against the belief of most Vedanta schools, which state that the Soul, the Self attain liberation. 

 It looks like the creator-creation theory is also borrowed from Abrahamic religion and on the base of a new belief system has been introduced giving it a Vedic outlook and propagating all non-Vedic rituals and worship by someone in the past.  

The vast ocean of Vedic religion or Santana Dharma was consistently steady and calm for a very long period. It appears that as a consequence of the rage of the Buddhist revolution, it got suddenly disturbed and flowed down to us in disorder. 

Even today Vedic religion or Santana Dharma has not recovered from the onslaught of Buddhism and Jainism and is not able to settle in people's hearts in its original form in the same old measure.

Hinduism indulges non-Vedic beliefs such as idolatry, ancestor worship, pilgrimages, priestcraft, offerings made in temples, the caste system, untouchability, and child marriages. All these lack Vedic sanction, therefore, Hinduism is not an Ancient Vedic religion or Santana Dharma.

All Hindu Gods are non-Vedic Gods. The Vedas exclaim from time immemorial: ~

Yajurveda – chapter- 32:~, God is  Supreme Spirit has no ‘Pratima’ (idol) or material shape. God cannot be seen directly by anyone. God pervades all beings and all directions. Thus,   Idolatry does not find any support from the Vedas.

Rig Veda, 1-164-146:~ Ekam Sat Vipra Bahudha Vadanti, Existence is One. 

God is one and universal.

God is the Spirit.  The Spirit is the Soul, the Self.  God is the Soul, the  Self.  The Soul is the Supreme Being the One eternal homogeneous essence, indivisible consciousness, and intelligence, which is beyond form, time, and space.   To which the Sages describe in a variety of ways through diverse words.

God is one and universal.

God is the Spirit.  The Spirit is the Soul, the Self.  God is the Soul, the  Self.  The Soul is the Supreme Being the One eternal homogeneous essence, indivisible consciousness and intelligence, which is beyond consciousness.   To which the Sages describe in a variety of ways through diverse words.

Rig Veda: ~ The Atman (Soul) is the cause; Atman is the support of all that exists in this universe. May ye never turn away from the Atman, the Self. May ye never accept another God in place of the Atman nor worship other than the Atman?" (10:48, 5)

Bhagavad Gita: ~ 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 (Gita 14.27)

The Upanishads say in effect that: ~ If you believe that the Soul is one and God (Brahman) is another you cannot understand Truth.

Brihad Upanishad: ~ “If you think there is another entity, whether man or God there is no truth."

Religion advocates extreme asceticism. Asceticism is a waste of time. Religion is nothing but remaining in the false belief, dogmas, and superstition.  

Mundaka Upanishad:~  The rituals and the sacrifices described in the Vedas deal with lower knowledge. The sages ignored these rituals and went in search of higher knowledge. ... Such rituals are unsafe rafts for crossing the sea of samsara, of birth and death. Doomed to shipwreck are those who try to cross the sea of Samsara on these poor rafts. Ignorant of their own ignorance, yet wise In their own esteem, these deluded men Proud of their vain learning go round and round Like the blind led by the blind.

Sage Sankara says: ~ “The scriptures dealing with rituals, and rewards are therefore addressed to an ignorant person. Thus, the rituals are meant for ignorant people.

Sage Sankara: ~ "Though I wear these robes of a Sanyasin, it is only for the sake of bread."

~ this shows he was wearing the religious robe only for the sake of bread." Thus, it means those who are wearing religious robes for the sake of bread.

All the rituals based on the false belief of Gods will not yield any fruits and they are meant for the ignorant populace who are unable to grasp the God beyond the form, time, and space.

One of Sage Sankara’s missions was to wean people away from a ritualistic approach advocated by Mimamsakas and to project wisdom (jnana) as the means of liberation in the light of Upanishad teachings.

Sage Sankara criticized severely the ritualistic attitude and those who advocated such practices. However, the orthodox texts that combined rituals with wisdom (jnana_karma_samucchaya) more in favor of the Mimamsaka position came into vogue, projecting Sage  Sankara as the rallying force of the doctrine.

Supreme Court of Hinduism, as a religion, incorporates all forms of belief without mandating the selection or elimination of any one single belief,“ It is a religion that has no single founder, no single scripture and no single set of teachings. It has been described as Santana Dharma, namely, eternal faith, as it is the collective wisdom and inspiration of the centuries that Hinduism seeks to preach and propagate,” ---Hinduism has no single founder or scripture: SC, The Times of India (Delhi) Dec 17, 2015

The Vedic system did not have a caste system.  The caste system was a fake created in the name of Hinduism. This non-Vedic belief system called Hinduism has created hatred in the low-caste Hindus for the higher caste. 

Conclusion: ~ 

Sage Sankara gave ritual, karma, and Upasana to people of lower and middling intellect which is followed by the Hindus of today as dualistic. Many founders of sect castes and groups of Hinduism were introduced with different scriptures different non-Vedic Gods and Goddesses and rituals.   

Hinduism is dualistic and has nothing to do with Sage Sankara’s Advaitic wisdom, which is nondualistic. Those who want to acquire self-knowledge or Brahma Gnana or Atma Gnana have to drop all the non-Vedic beliefs, which is a hindrance in the path of wisdom.

Sage Sankara's wisdom has nothing to do with Hinduism. Sage Sankara’s Advaitic wisdom is the pure Vedic essence of the Vedic religion or Santana Dharma. : ~ Santthosh Kumaar