As soon as a sleeping living entity hears the powerful voice emanating from the mouth of a pure devotee, he immediately remembers his eternal relationship with the Lord, although up until that moment he had forgotten everything.
For a conditioned soul, therefore, it is very important to hear from the mouth of a pure devotee, who is fully surrendered to the lotus feet of the Lord without any material desire, speculative knowledge or contamination of the modes of material nature. Every one of us is kuyogi because we have engaged in the service of this material world, forgetting our eternal relationship with the Lord as His eternal loving servants. It is our duty to rise from the kuyoga platform to become suyogis, perfect mystics. The process of hearing from a pure devotee is recommended in all Vedic scriptures, especially by Lord Caitanya Mahaprabhu. One may stay in his position of life — it does not matter what it is — but if one hears from the mouth of a pure devotee, he gradually comes to the understanding of his relationship with the Lord and thus engages in His loving service, and his life becomes completely perfect.
Srila Prabhupada/ SB 4.20.25 purport