Srimad-Bhagavatam: Canto 7 - Chapter 1 - Verse 3
भृत्यलक्षणजिज्ञासुर्भक्तं कामेष्वचोदयत् ।भवान् संसारबीजेषु हृदयग्रन्थिषु प्रभो ॥ ३ ॥
bhṛtya-lakṣaṇa-jijñāsurbhaktaṁ kāmeṣv acodayatbhavān saṁsāra-bījeṣuhṛdaya-granthiṣu prabho
O my worshipable Lord, because the seed of lusty desires, which is the root cause of material existence, is within the core of everyone’s heart, You have sent me to this material world to exhibit the symptoms of a pure devotee.
Bhakti-rasāmṛta-sindhu has given considerable discussion about nitya-siddha and sādhana-siddha devotees. Nitya-siddha devotees come from Vaikuṇṭha to this material world to teach, by their personal example, how to become a devotee. The living entities in this material world can take lessons from such nitya-siddha devotees and thus become inclined to return home, back to Godhead. A nitya-siddha devotee comes from Vaikuṇṭha upon the order of the Supreme Personality of Godhead and shows by his example how to become a pure devotee (anyābhilāṣitā-śūnyam). In spite of coming to this material world, the nitya-siddha devotee is never attracted by the allurements of material enjoyment. A perfect example is Prahlāda Mahārāja, who was a nitya-siddha, a mahā-bhāgavata devotee. Although Prahlāda was born in the family of Hiraṇyakaśipu, an atheist, he was never attached to any kind of materialistic enjoyment. Desiring to exhibit the symptoms of a pure devotee, the Lord tried to induce Prahlāda Mahārāja to take material benedictions, but Prahlāda Mahārāja did not accept them. On the contrary, by his personal example he showed the symptoms of a pure devotee. In other words, the Lord Himself has no desire to send His pure devotee to this material world, nor does a devotee have any material purpose in coming. When the Lord Himself appears as an incarnation within this material world, He is not allured by the material atmosphere, and He has nothing to do with material activity, yet by His example He teaches the common man how to become a devotee. Similarly, a devotee who comes here in accordance with the order of the Supreme Lord shows by his personal behavior how to become a pure devotee. A pure devotee, therefore, is a practical example for all living entities, including Lord Brahmā.