Prahlada Maharaja simply followed the instructions of Narada Muni, his guru, and thus he always remained a stalwart devotee. This is the nature of an intelligent devotee
SB Canto 7
Prahlāda Mahārāja, you are certainly a self-realized soul and a devotee of the Supreme Lord. You do not care for public opinion or so-called scriptures. For this reason I have described to you without hesitation the history of my self-realization.
A person who is actually a devotee of Kṛṣṇa does not care about so-called public opinion and Vedic or philosophical literatures. Prahlāda Mahārāja, who is such a devotee, always defied the false instructions of his father and the so-called teachers who were appointed to teach him. Instead, he simply followed the instructions of Nārada Muni, his guru, and thus he always remained a stalwart devotee. This is the nature of an intelligent devotee. The Śrīmad-Bhāgavatam instructs, yajñaiḥ saṅkīrtana-prāyair yajanti hi sumedhasaḥ (SB 11.5.32). One who is actually very intelligent must join the Kṛṣṇa consciousness movement, realizing his own self as an eternal servant of Kṛṣṇa, and thus practice constant chanting of the holy name of the Lord—Hare Kṛṣṇa, Hare Kṛṣṇa, Kṛṣṇa Kṛṣṇa, Hare Hare/ Hare Rāma, Hare Rāma, Rāma Rāma, Hare Hare.