Srila Prabhupada, can realization be had through service without theoretical understanding?

Expressions researched:
"Srila Prabhupada, can realization be had through service without theoretical understanding"

1976 Conversations and Morning Walks

This whole science is understood through service only. Everything is revelation. Unless one is very sincere servant, there is no revelation.

Garden Conversation -- June 27, 1976, New Vrindaban:

Puṣṭa Kṛṣṇa: Can these things be understood theoretically, Śrīla Prabhupāda, or is realization required?

Prabhupāda: Realization required. What is the use of theoretical knowledge?

Devotee (2): Śrīla Prabhupāda, can realization be had through service without theoretical understanding?

Prabhupāda: This whole science is understood through service only. Everything becomes revealed. Sevonmukhe hi jihvādau svayam eva sphuraty adaḥ (Bhakti-rasāmṛta-sindhu 1.2.234). Revelation. Everything is revelation. Unless one is very sincere servant, there is no revelation.