From a clear knowledge of the Bhagavad-gita all the goals of human existence become fulfilled. Bhagavad-gita is the manifest quintessence of all the teachings of the Vedic scriptures.
Adi ShankaraDo 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.
Adi ShankaraBut the jiva [living being] is endowed with ego and his knowledge is limited, whereas Ishwar is without ego and is omniscient.
Adi ShankaraEven 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.
Adi Shankara