Prabhupada Letters :: 1968.

"Simply by understanding Krishna, one understands everything. Therefore, Krishna being the Supreme Spirit, one who tries to understand Krishna, he can understand everything else."

Prabhupada Letters :: 1975.

"By chanting and giving prasadam you will get so many devotees। Purity is attractive. Our only asset is our purity. You cannot reach Krsna without being pure, because He is the supreme pure."

Śrī Brahma-saṁhitā, Lecture New York, July 28, 1971.

"Govindam ādi-puruṣam tam ahaṁ bhajāmi ।We are worshiping the original person, ādi-puruṣam। Original person... As we are all persons, our origin is also a person. We should always understand this. Ādi-puruṣam. The same example. Unless my forefather was a person, how his son, his son, his son—I am the last—we are persons? So the original father, the supreme father, or God, or Kṛṣṇa, must be a person, not imperson. We should always remember. Govindam ādi-puruṣam tam ahaṁ bhajāmi".

We are worshiping the original person, original person... As we are all persons, our origin is also a person। We should always understand this. The same example. Unless my forefather was a person, how his son, his son, his son—I am the last—we are persons? So the original father, the supreme father, or God, or Kṛṣṇa, must be a person, not imperson. We should always remember.

Prabhupada Letters :: 1974.

"If the guru is a representative of the Supreme Lord in disciplic succession and the student is sincere, only then he can get him out of the clutches of the material energy."