yasya deve parā bhaktir yathā deve tathā gurau tasyaite kathitā hy arthaḥ prakāśante mahātmanaḥ [Śvetāśvatara Upaniṣad

"Only unto one who has unflinching devotion to the Lord and to the spiritual master does transcendental knowledge become automatically revealed." Such a relationship between the disciple and the spiritual master is eternal. One who is now the disciple is the next spiritual master. And one cannot be a bona fide and authorized spiritual master unless one has been strictly obedient to his spiritual master. Brahmaji, as disciple of the Supreme Lord, received the real knowledge and imparted it to his dear disciple Narada, and similarly Narada, as spiritual master, handed over this knowledge to Vyasa and so on. Therefore the so-called formal spiritual master and disciple are not facsimiles of Brahma and Narada or Narada or Vyasa. The relationship between Brahma and Narada is reality, while the so-called formality is the relation between the cheater and cheated. It is clearly mentioned herewith that Narada is not only well behaved, meek and obedient, but is also self-controlled. One who is not self-controlled, specifically in sex life, can neither become a disciple nor a spiritual master. One must have disciplinary training in controlling speaking, anger, tongue, mind, belly and the genitals. One who has controlled the particular senses mentioned above is called a gosvami. Without becoming a gosvami one can neither become a disciple nor a spiritual master. The so-called spiritual master without sense control is certainly the cheater, and the disciple of such a so-called spiritual master is the cheated.