Srila Prabhupada, Los Angeles, November 18, 1968: [...] Simply by studying, becoming bookworm, you cannot advance. The real secret is that is stated in the Vedas. Unflinching faith in God and spiritual master. Then things will be revealed from within.
How much strength we have got to study all these books? But Vedas says, yasya deve para bhaktir yatha deve tatha gurau. If one has got unflinching faith in God and similar faith in the spiritual master, tasyaite kathita hy arthah prakasante mahatmanah, to him only the Vedic knowledge becomes revealed.
And this is also confirmed in the Bhagavad-gita. Lord Krishna says, tenam satata-yuktanam bhajatam priti-purvakam: [Bg. 10.10] “Those who are engaged in My service with love and affection, buddhi-yogam dadami tam, I personally give him intelligence, yena mam upayanti te, by which he can come to Me.”
In another place, it is stated in the Bhagavad-gita, tenam evanukampartham: [Bg. 10.11] “In order to show these devotees special favor, tenam evanukampartham aham ajnana-jam tamah nasayamy, I personally dissipate their darkness within the heart.” Everything, the mind is full of darkness; therefore we are conditioned.
So Krishna, from within He drives away the darkness of ignorance. Aham ajnana-jam tamah nasayamy. Aham ajnana-jam tamah nasayamy atma-bhava, just like that.