When a pure devotee or spiritual master speak, what he says should be accepted as having been directly spoken by the Supreme Personality of Godhead in the Parampara System. — Sri Caitanya Caritamrita, Antya Lila, 05.71.
To travel in another country, you need visa permission, similarly to go back to Godhead you need permission & mercy from his pure devotee.
Krishna does not agree to award devotional service to merely anyone. Krishna can easily offer a person material happiness or even liberation, but He does not agree very easily to award a person engagement in his devotional service. Devotional service can in fact be attained only through the mercy of a pure devotee. — The Nectar of Devotion, Page 14.
A pure devotee of the Lord accepts tribulation as favours from the Lord. Since the Lord is absoulte, there is no mundane difference between the two. (Between tribulation and favours). — Srimad Bhagavatam, 01.09.17.
Only a pure devotee, whom we deem to be a vaishnava, can be considered sinless.
Pure devotees, who take transcendental pleasure in hearing and chanting the glories of the Lord, do not care for any kind of liberation; even if they are offered the five liberations, they refuse to accept them