My dear , if we want to achieve the perfection of going back to Home, back to Godhead we must learn how to master the art of hearing submissively from the bona fide spiritual master. The bona fide spiritual master does not concoct his own teachings. If he does so, he is not bona fide. The bona fide spiritual master purely presents without any
addition or subtraction the pure teachings that are going down in disciplic succession from previous acharyas. This process of now the authorized knowledge is coming to us is described in the Bhagavad-gita, Chapter 4, Text 2:
evaṁ paramparā-prāptam
imaṁ rājarṣayo viduḥ
sa kāleneha mahatā
yogo naṣṭaḥ parantapa
"This supreme science was thus received through the chain of disciplic succession, and the saintly kings understood it in that way. But in course of time the succession was broken, and therefore the science as it is appears to be lost."
Those who take their training from the bona fide spiritual become liberated from this material existence. Those who do not remain entangled here in the cycle of repeated birth and death.