Bhagavad Gita 4.34
tad viddhi pranipatena pariprasnena sevaya
upadeksyanti te jnanam jnaninas tattva-darsinah
Know the Supreme Lord. Know Him by surrendering to Him, by questioning and by service. A seeker of truth will realize divine knowledge when they approach an enlightened jnani and accept them as their Guru. A self-realized jnani can impart knowledge to you because they know the truth.
Sri Bhakti Siddhanta Saraswati Goswami:
The essential principle of Vaishnavism is that however great a scholar and intellectual giant a man may be, he will not be able to appreciate even the easiest points of Vaishnava philosophy until and unless he has entirely surrendered himself to an Acharya whose character is the embodiment of the Vaishnava philosophy. The Gita declares the Vaishnava philosophy is understandable only with unconditional surrender, honest inquiry and a serving temperament. It is only after an approach to a genuine professor of Vaishnava philosophy with these three as the fee, that they give instructions about the correct philosophical truths. These professors are never tempted by any type of worldly fee.
