Srimad-Bhagavatam: Canto 5 - Chapter 1 - Verse 26
तस्य महानुभावस्यानुपथममृजितकषाय: को वास्मद्विध: परिहीणभगवदनुग्रह उपजिगमिषतीति ॥ २६ ॥
tasya mahānubhāvasyānupatham amṛjita-kaṣāyaḥ ko vāsmad-vidhaḥ parihīṇa-bhagavad-anugraha upajigamiṣatīti.
Bali Mahārāja said: Persons like us, who are still attached to material enjoyment, who are contaminated by the modes of material nature and who lack the mercy of the Supreme Personality of Godhead, cannot follow the supreme path of Prahlāda Mahārāja, the exalted devotee of the Lord.
It is said that for spiritual realization one must follow great personalities like Lord Brahmā, Devarṣi Nārada, Lord Śiva and Prahlāda Mahārāja. The path of bhakti is not at all difficult if we follow in the footsteps of previous ācāryas and authorities, but those who are too materially contaminated by the modes of material nature cannot follow them. Although Bali Mahārāja was actually following the path of his grandfather, because of his great humility he thought that he was not. It is characteristic of advanced Vaiṣṇavas following the principles of bhakti that they think themselves ordinary human beings. This is not an artificial exhibition of humility; a Vaiṣṇava sincerely thinks this way and therefore never admits his exalted position.