Prahlāda Mahārāja's recommendation is very genuine. That is the Vedic system. But he was unfortunately born in a asura family. His father was a great asura. Asura means godless. He had also undergone severe austerity to achieve the power. He was defeated by the demigods. So he left his home and underwent severe austerities so that the whole universe became trembled and Brahmājī came to appease him, "What do you want?" He said: "I want to become immortal." So Brahmājī said, "How can I give you this benediction of immortality, because myself I am not immortal?" Everyone has to die in this material world, either one may be Brahmā or a small ant. Janma-mṛtyu-jarā-vyādhi-duḥkha-doṣānudarśanam (BG 13.9). "So this is not possible. I cannot make you immortal."
Then very diligently he said: "All right, then no man will kill me."
"All right, accepted."
"No demigod will kill me."
"Also accepted."
"I shall not die at daytime."
"That's all right."
"I shall not die in night."
"That's all right."
"No animal can kill me."
"That's all right."
"No weapons can kill me."
"That's all right."
In this way, he thought that, "I am very intelligent and I am cheating Brahmājī. Indirectly, by different way, I have now become immortal."
So he also underwent great austerities, but for material enjoyment. He wanted to live forever in this material world. So he was never interested to teach his children about Kṛṣṇa consciousness. But Prahlāda Mahārāja, fortunately, when he was in the womb of his mother, at the care of Nārada Muni, he understood the Kṛṣṇa consciousness, because if you associate with a sādhu, the saintly person, then saintly person has nothing to do but simply deliver the knowledge, transcendental knowledge, of Kṛṣṇa consciousness. They have no other duty.