"The pure devotees are honored by the names Prabhupāda and Viṣṇupāda"

"To take shelter of the lotus feet of the Lord means to take shelter of the pure devotees. The pure devotees whose only business is serving are honored by the names Prabhupāda and Viṣṇupāda, which indicate such devotees to be representatives of the lotus feet of the Lord. Anyone, therefore, who takes shelter of the lotus feet of a pure devotee by accepting the pure devotee as his spiritual master can be at once purified. 

Such devotees of the Lord are honored equally with the Lord because they are engaged in the most confidential service of the Lord, for they deliver out of the material world the fallen souls whom the Lord wants to return home, back to Godhead. 

Such pure devotees are better known as vice-lords according to revealed scriptures. The sincere disciple of the pure devotee considers the spiritual master equal to the Lord, but always considers himself to be a humble servant of the servant of the Lord [Cc. Madhya 13.80]. This is the pure devotional path."

Śrīmad-Bhāgavatam 1.1.15