Spiritual knowledge is a matter of Guruparampara. It is handed down from a Guru to his disciple. Study Brihadaranyaka Upanishad. You will have a comprehensive understanding. Gaudapadacharya imparted Self-knowledge to his disciple Govindapadacharya; Govindapadacharya to his disciple Sankaracharya; Sankaracharya to his disciple Suresvaracharya. Gorakhnath to Nivrittinath; Nivrittinath to Jnanadev. Totapuri imparted knowledge to Ramakrishna; Ramakrishna to Vivekananda. It was Dr. Annie Besant who moulded the career of Sri Krishnamurthi. It was Ashtavakra who moulded the life of Raja Janaka. It was Gorakhnath who shaped the spiritual destiny of Raja Bhartrihari. It was Lord Krishna who made Arjuna and Uddhava establish themselves in the spiritual path, when their minds were in an unsettled condition.
Some aspirants do meditation for some years independently. Later on they feel actually the necessity for a Guru. They come across some obstacles in the way. They do not know how to proceed further and how to obviate these impediments or stumbling blocks. Then they begin to search for a Guru.The student and the teacher should live together as father and devoted son or as a husband and wife with extreme sincerity and devotion. The aspirant should have an eager, receptive attitude to imbibe the teachings of the master. Then only will the aspirant be spiritually benefited; otherwise, there is not the least hope of the spiritual life of the aspirant and complete regeneration of his old Asuric nature.
It is a great pity that the present system of education in India is not favourable to the spiritual growth of Sadhakas. The minds of the students are saturated with materialistic poison. Aspirants of the present day have not got any idea of the true relationship of Guru and a disciple. It is not like the relationship of a student and teacher or professor in schools and colleges. Spiritual relationship is entirely different. It involves dedication. It is very sacred. It is purely divine. Turn the pages of the Upanishads. In days of yore, Brahmacharins used to approach their teachers with profound humility, sincerity and Bhava.