Spiritual knowledge descends through an unbroken chain of teachers and disciples. This ensures the message remains unchanged. The Bhagavad-gita Introduction explains that the Bhagavad-gita itself was transmitted through parampara from Krishna to Arjuna, establishing a new succession. The Bhagavad-gita (4.1-3) teaches that knowledge must come through authorized channels and that personal interpretation breaks the succession. The message must be received 'as it is,' and Srila Prabhupada represents this succession in modern times.