Sage Sankara explains in Manduka upanishad that those who study the Sutras are orthodox minds, intellectual children, hence his popular view point to assist them.+

Advaitic wisdom is independent of religion.  Sage Sankara himself the Saguna Brahman, or a personal God is only a part of the phenomenal (if not illusory) world and the Nirguna Brahman is the only reality and has nothing to do with religion.  

It is very difficult to bifurcate the pearls of the hidden wisdom of Sage Sankara from the contamination of theistic Advaita and Advaita Vedanta.   

Sage Sankara's wisdom (Advaita) ~ Without a Parallel.  Sage Sankara's wisdom is lofty, sublime, and unique. It is highly interesting, inspiring, and elevating. No other wisdom can stand before it in boldness, depth, and subtle thinking.  Sage Sankara’s wisdom is complete and perfect.

Sage Sankara was a mighty, marvelous genius. He was a profound thinker of the first rank. He was a sage of the highest realization. His wisdom has brought solace, peace, and illumination to countless persons in the world. The Western thinkers bow their heads at the lotus-feet of Sage Sankara. His wisdom has soothed the sorrows and afflictions of the most forlorn persons and brought hope, joy, wisdom, perfection, freedom, and calmness to many. His wisdom commands the admiration of the whole world.

Sage Sankara pokes fun at ascetics and points out that all their austerities do not cause desires to go (Altar Flowers" Page 205, v.2 P.207 v.4)

The Brahma Sutras together with Sage Sankara's commentary thereon do not contain the higher wisdom. They are intended for those who are incapable of thinking rationally.

Sage Sankara's commentary on the Brahma Sutras is not on a philosophical basis, but on an orthodox and mystic basis, with an appeal to the Vedas as a final authority.

In Brahma Sutra Sage Sankara takes the position that there is another entity outside us, i.e. the wall really exists separately from the mind. This was because Sage  Sankara explains in Manduka that those who study the Sutras are orthodox minds, intellectual children, hence his popular viewpoint to assist them. These people are afraid to go deeper because it means being heroic enough to refuse to accept Sruti, and God's authority, in case they mean punishment by God.  A Gnani says the scriptures for children, but wise seekers will think rationally.

In Brahma Sutras Sage Sankara takes for granted, assumes that a world was created: He there mixes dogmatic theology with philosophy.

That God created the world is an absolute lie, nevertheless one will find Sage  Sankara (in his commentary on Vedanta Sutras) clearly says this! He has to adapt his teachings to his audience, reserving the highest for philosophical minds.

The text of Brahma Sutras is based on religion, dogmatism, but in the commentary Sage  Sankara cleverly introduced some philosophy. If it is objected that a number of Upanishads are equally dogmatic because they also begin by assuming Brahman, only a few Upanishads do not but prove Brahman at the end of a train of proof.

Scholars' translation of Brahma Sutras in Sacred Books of East must be read cautiously as he has not understood its highest sense, e.g. for Advaita, they wrongly put "Unity" instead of “Non-duality."

Sage Sankara gave religion and scholasticism and yoga no less than philosophy, to the seeking world. He was great enough to be able to do so. His commentary on Mandukya is pure philosophy, but many of his other books are presented from a religious standpoint to help those who cannot rise up to philosophy.

Advatic Orthodoxy is the home of mysticism and deification that is why they are not very keen on rational truth.

Sage Sankara is a Jagaduru to the religious followers and he is a Brahma Gnani to the seeking world.  :~Santthosh Kumaar