How can one attain perfection within a single lifetime?
Answer: If one gives up one's free will and fully surrenders to Sri Gurudeva, and then performs bhajana without duplicity under his guidance, one will attain perfection within a single lifetime.
Where does a person find his guru?
Answer: Whoever Sri Krishna, the embodiment of compassion, chooses to send to you as your guru, that person alone will manifest before you externally as the mahanta-guru, the guru in the form of the foremost living sadhu. By the mercy of Bhagavan we will obtain a guru, and by the mercy of the guru we can attain Bhagavan.
A person will get a guru according to his particular destiny. People of different types vary in their disposition, and therefore Bhagavan, who is omniscient, sends them each a particular type of guru. There are those who want nishkapata-kripa, the real mercy of Bhagavan, and who depend entirely on Bhagavan for their eternal welfare. Being pleased with such simple-hearted, sincere persons, Bhagavan Himself manifests before them as the guru, to bestow mercy upon them.
But for those who want kapata-kripa, the deceptive mercy of Bhagavan, Bhagavans maya, or external potency, will send them a guru according to the particular disposition of their heart.
There is no impediment for one who is sincere. He will very quickly meet a bona fide guru.
What is the most severe nama-aparadha, or offence to the holy name?
Answer: To consider Srila Gurudeva to be an ordinary human being is the most deadly offence, the most severe nama-aparadha. By maintaining a conception of him as a mere mortal, one cannot attain auspiciousness even in billions of births. A person with such a mundane conception of the guru will encounter various types of obstacles in bhakti and will be in danger of drowning in the ocean of material desires. Besides the lotus feet of Sri Guru, nothing can save us from the clutches of harmful association. The jiva is unable to surrender himself at the lotus feet of Sri Gurudeva only because he considers Sri Gurudeva to be an ordinary human being.
What is the function of the acharya?
Answer: The acharya carries the message of Sri Bhagavan. He comes to us to deliver the message of Vaikuntha. One must accept that message of Vaikuntha emanating from the lotus lips of Sri Guru through ears imbued with a service mood. If there is full surrender, then by the mercy of the acharya one can attain everything. No one besides the residents of Vaikuntha can accurately deliver the message of Vaikuntha. To learn about Calcutta, you must hear from one who has seen Calcutta. Only then can you receive true information about Calcutta.