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.