In Bhagavad-gītā (10.11) it is said:

teṣām evānukampārtham aham ajṣāna-jaṁ tamaḥ nāśayāmy ātma-bhāva stho jṣāna-dīpena bhāsvatā

For a devotee who has taken the lotus feet of the Lord within his heart, the Lord gives spiritual enlightenment, known as jṣāna-dīpa, by special mercy from within. This jṣāna-dīpa is compared to the fire hidden within araṇi wood. To perform fire sacrifices, great sages previously did not ignite a fire directly; the fire would be invoked from araṇi wood. Similarly, all living entities are covered by the modes of material nature, and the fire of knowledge can be ignited only by the Supreme Personality of Godhead when one takes Him within one’s heart. Sa vai manaḥ kṛṣṇa-padāravindayoḥ. If one takes seriously the lotus feet of Kṛṣṇa, who is seated within one’s heart, the Lord eradicates all ignorance. By the torch of knowledge, one immediately understands everything properly by the special mercy of the Supreme Lord and becomes self-realized. In other words, although a devotee may externally not be very well educated, because of his devotional service the Supreme Personality of Godhead gives him enlightenment from within. If the Lord gives enlightenment from within, how can one be in ignorance? Therefore the allegation of the Māyāvādīs that the devotional path is for the unintelligent or uneducated is untrue.

yasyāsti bhaktir bhagavaty akiṣcanā sarvair guṇais tatra samāsate surāḥ

If one becomes an unalloyed devotee of the Supreme Lord, he automatically manifests all good qualities. Such a devotee is above the instructions of the Vedas. He is a paramahaṁsa. Even without going through the Vedic literature, a devotee becomes pure and enlightened by the mercy of the Lord. “Therefore, my Lord,” the devotee says, “I offer my respectful obeisances unto You.”