The proof that the spiritual master is bona fide is his invincible faith in God, which protects him from the calamity of impersonalism
Other Books by Srila Prabhupada
Mukunda-mala-stotra (mantras 1 to 6 only)
King Kulaśekhara is a pure devotee, and as such he is not eager to improve himself by the standards of the empiric philosophers, distressed men, or fruitive workers of this world. Pious acts may lead a mundane creature toward the path of spiritual realization, but practical activity in the domain of devotional service to the Lord need not wait for the reactions of pious acts. A pure devotee does not think in terms of his personal gain or loss because he is fully surrendered to the Lord. He is concerned only with the service of the Lord and always engages in that service, and for this reason his heart is the Lord's home. The Lord being absolute, there is no difference between Him and His service. A pure devotee's heart is always filled with ideas about executing the Lord's service, which is bestowed upon the pure devotee through the transparent medium of the spiritual master.
The spiritual master in the authoritative line of disciplic succession is the "son of God," or in other words the Lord's bona fide representative. The proof that he is bona fide is his invincible faith in God, which protects him from the calamity of impersonalism. An impersonalist cannot be a bona fide spiritual master, for such a spiritual master's only purpose in life must be to render service to the Lord. He preaches the message of Godhead as the Lord's appointed agent and has nothing to do with sense gratification or the mundane wrangling of the impersonalists. No one can render devotional service to an impersonal entity because such service implies a reciprocal personal relationship between the servant and the master. In the impersonal school the so-called devotee is supposed to merge with the Lord and lose his separate existence.
Pure devotees like King Kulaśekhara are particularly careful to avoid a process that will end in their becoming one with the existence of the Lord, a state known as advandva, nonduality. This is simply spiritual suicide. Out of the five kinds of salvation, advandva is the most abominable for a devotee. A pure devotee denounces such oneness with the Lord as worse than going to hell.