Ādi) Śaṅkarācārya works in Sanskrit discuss the unity of the ātman and Nirguna Brahman “brahman without attributes”.He wrote copious commentaries on the Vedic canon (Brahma Sutras, Principal Upanishads and Bhagavad Gita) in support of his thesis.His works elaborate on ideas found in the Upanishads. Shankara’s publications criticised the ritually-oriented Mīmāṃsā school of Hinduism. He also explained the key difference between Hinduism and Buddhism, 
stating that Hinduism asserts “Atman (Soul, Self) exists”, while Buddhism asserts that there is “no Soul, no Self”.
Ādi) Śaṅkarācārya travelled across the Indian subcontinent to propagate his philosophy through discourses and debates with other thinkers. He established the importance of monastic life as sanctioned in the Upanishads and Brahma Sutra, in a time when the Mīmāṃsā school established strict ritualism and ridiculed monasticism. He is reputed to have founded four mathas (“monasteries”), which helped in the historical development, revival and spread of Advaita Vedanta of which he is known as the greatest revivalist. Adi Shankara is believed to be the organiser of the Dashanami monastic order and unified the Shanmata tradition of worship. He is also known as Adi Shankaracharya, Shankara Bhagavatpada, sometimes spelled as Sankaracharya, (Ādi) Śaṅkarācārya, Śaṅkara Bhagavatpāda and Śaṅkara Bhagavatpādācārya.
Do not be proud of wealth, people, relations and friends, or youth. All these are snatched by time in the blink of an eye. Giving up this illusory world, know and attain the Supreme.
Do not look at anybody in terms of friend or foe, brother or cousin; do not fritter away your mental energies in thoughts of friendship or enemity. Seeking the Self everywhere, be amiable and equal-minded towards all, treating all alike.
Even after the Truth has been realised, there remains that strong, obstinate impression that one is still an ego – the agent and experiencer. This has to be carefully removed by living in a state of constant identification with the supreme non-dual Self. Full Awakening is the eventual ceasing of all the mental impressions of being an ego.
Reality can be experienced only with the eye of understanding, not just by a scholar.
The world, like a dream full of attachments and aversions seems real until the awakening.
