aham ajnana-jam tamah
tesam—for them; eva—certainly; anukampa-artham—to show special mercy; aham—I; ajnana-jam—due to ignorance; tamah—darkness; nasayami—dispel; atma—within; bhavasthah—themselves; jnana—of knowledge; dipena—with the lamp; bhasvata—glowing.
Out of compassion for them, I, dwelling in their hearts, destroy with the shining lamp of knowledge the darkness born of ignorance.
When Lord Caitanya was in Benares promulgating the chanting of Hare Krsna, Hare Krsna, Krsna Krsna, Hare Hare/ Hare Rama, Hare Rama, Rama Rama, Hare Hare, thousands of people were following Him. Prakasananda, a very influential and learned scholar in Benares at that time, derided Lord Caitanya for being a sentimentalist. Sometimes philosophers criticize the devotees because they think that most of the devotees are in the darkness of ignorance and are philosophically naive sentimentalists. Actually that is not the fact. There are very, very learned scholars who have put forward the philosophy of devotion, but even if a devotee does not take advantage of their literatures or of his spiritual master, if he is sincere in his devotional service he is helped by Krsna Himself within his heart. So the sincere devotee engaged in Krsna consciousness cannot be without knowledge. The only qualification is that one carry out devotional service in full Krsna consciousness.
The modern philosophers think that without discriminating one cannot have pure knowledge. For them this answer is given by the Supreme Lord: those who are engaged in pure devotional service, even though they be without sufficient education and even without sufficient knowledge of the Vedic principles, are still helped by the Supreme God, as stated in this verse.
The Lord tells Arjuna that basically there is no possibility of understanding the Supreme Truth, the Absolute Truth, the Supreme Personality of Godhead, simply by speculating, for the Supreme Truth is so great that it is not possible to understand Him or to achieve Him simply by making a mental effort. Man can go on speculating for several millions of years, and if he is not devoted, if he is not a lover of the Supreme Truth, he will never understand Krsna or the Supreme Truth. Only by devotional service is the Supreme Truth, Krsna, pleased, and by His inconceivable energy He can reveal Himself to the heart of the pure devotee. The pure devotee always has Krsna within his heart; therefore he is just like the sun that dissipates the darkness of ignorance. This is the special mercy rendered to the pure devotee by Krsna.
Due to the contamination of material association, through many, many millions of births, one's heart is always covered with the dust of materialism, but when one engages in devotional service and constantly chants Hare Krsna, the dust quickly clears, and one is elevated to the platform of pure knowledge. The ultimate goal of Visnu can be attained only by this chant and by devotional service, and not by mental speculation or argument. The pure devotee does not have to worry about the necessities of life; he need not be anxious because when he removes the darkness from his heart, everything is provided automatically by the Supreme Lord, for He is pleased by the loving devotional service of the devotee. This is the essence of the Gita's teachings. By studying Bhagavad-gita, one can become a completely surrendered soul to the Supreme Lord and engage himself in pure devotional service. As the Lord takes charge, one becomes completely free from all kinds of materialistic endeavors.
Link to this page: https://prabhupadabooks.com/bg/10/11