Srimad-Bhagavatam: Canto 6 - Chapter 1 - Verse 19

Sanskrit:

मरुतश्च दिते:पुत्राश्चत्वारिंशन्नवाधिका: ।त आसन्नप्रजा: सर्वे नीता इन्द्रेणसात्मताम् ॥ १९ ॥

ITRANS:

marutaś ca diteḥ putrāścatvāriṁśan navādhikāḥta āsann aprajāḥ sarvenītā indreṇa sātmatām

Translation:

The forty-nine Marut demigods were also born from the womb of Diti. None of them had sons. Although they were born of Diti, King Indra gave them a position as demigods.

Purport:

Apparently even demons can be elevated to positions as demigods when their atheistic character is reformed. There are two kinds of men throughout the universe. Those who are devotees of Lord Viṣṇu are called demigods, and those who are just the opposite are called demons. Even the demons can be transformed into demigods, as the statement of this verse proves.