This natural attraction for Kṛṣṇa on the part of Prahlāda was developed simply by the mercy of Nārada. When Prahlāda Mahārāja was within the womb of his mother, she was being sympathetically instructed by Nārada about the science of devotional service, and at the same time Nārada was wishing that the child within the womb could also take advantage of the instructions. Because Nārada, an authorized devotee and great associate of the Personality of Godhead, was desiring auspiciousness for Prahlāda Mahārāja, he developed all the characteristics of a high-grade devotee. This is called natural attraction. It is caused by the special grace of the Personality of Godhead or by the special grace of a great devotee like Nārada.
There is a statement in the Skanda Purāṇa wherein Parvata Muni tells Nārada, "My dear Nārada, of all saintly persons you are so great and glorious that simply by your good wishes a lowborn hunter also has become a great, elevated devotee of Lord Kṛṣṇa."
This ecstatic love for Kṛṣṇa can be divided into five divisions, which will be described by Śrī Rūpa Gosvāmī later on.