By the mercy of the spiritual master one is benedicted by the mercy of Krsna. Without the grace of the spiritual master, one cannot make any advancement. A disciple should never be a hypocrite or be unfaithful to his spiritual master. In Srimad-Bhagavatam (11.17.27), the spiritual master is also called acarya. Acaryam mam vijaniyan: the Supreme Personality of Godhead says that one should respect the spiritual master, accepting him as the Lord Himself. Navamanyeta karhicit: one should not disrespect the acarya at any time. Na martya-buddhyasuyeta: one should never think the acarya an ordinary person. Familiarity sometimes breeds contempt, but one should be very careful in ones dealings with the acarya. Agadha-dhisanam dvijam: the acarya is a perfect brahmana and has unlimited intelligence in guiding the activities of his disciple. Therefore Krsna advises in Bhagavad-gita (4.34):

Just try to learn the truth by approaching a spiritual master. Inquire from him submissively and render service unto him. The self-realized soul can impart knowledge unto you because he has seen the truth. One should fully surrender unto the spiritual master. and with service (sevaya) one should approach him for further spiritual enlightenment.