What is Ego?

The belief that "I am John" is ego. In reality, you are pure Soul. To realize this, true knowledge is required. A Gnani(Self realized person) can grace you with this.
To know more visit: http://www.dadabhagwan.org/path-to-happiness/spiritual-science/who-am-i-realize-your-true-self/what-is-ego-who-am-i-really/
http://www.dadabhagwan.org/path-to-happiness/spiritual-science/what-is-ego-egoism/