Prabhupada Letters :: 1970.

"Lord Caitanya has warned. Don't mix with any Swami who has no knowledge of Krsna Consciousness. Their speaking is simply maya. Anyone who listens to their philosophy is doomed, all devotion dries up."

Prabhupada Letters :: 1968.

"My books are the ultimate source of knowledge. If you simply reproduce what I have explained surely you will come out victorious, even in the midst of so many great scholars."

Prabhupada Letters :: 1969.

"We cannot demand from Krishna to know about Him. When you actually learn to serve Him, He reveals Himself. Knowledge means to know Him, and success means to please Him. And how Krishna is pleased, that can be known through the transparent medium of His confidential servant."