CC Madhya 24.205

kṛṣṇa-kṛpādi-hetu haite sabāra udaya
kṛṣṇa-guṇākṛṣṭa hañā tāṅhāre bhajaya
Synonyms: 
kṛṣṇa-kṛpā-ādi-hetu — the reason of Kṛṣṇa’s mercy; haite — from; sabāra udaya — anyone becomes a devotee; kṛṣṇa-guṇa-ākṛṣṭa hañā — being attracted by the transcendental qualities of Kṛṣṇa; tāṅhāre — Him; bhajaya — worship.
Translation: 
“Everyone is eligible to receive Kṛṣṇa’s mercy — including Vyāsadeva, the four Kumāras, Śukadeva Gosvāmī, lowborn creatures, trees, plants and beasts. By Kṛṣṇa’s mercy they are elevated and engaged in His service.
Purport: 

This is confirmed in the Bhagavad-gītā (9.32), wherein the Lord says:

māṁ hi pārtha vyapāśrityaye ’pi syuḥ pāpa-yonayaḥ
striyo vaiśyās tathā śūdrās
te ’pi yānti parāṁ gatim

“O son of Pṛthā, those who take shelter in Me, though they be of lower birth — women, vaiśyas [merchants] and śūdras [workers] — can attain the supreme destination.”

Everyone is eligible to become Kṛṣṇa’s devotee. One simply has to be trained according to the approved process. It is the work of Kṛṣṇa’s confidential devotees to turn everyone into a Kṛṣṇa bhakta. If the confidential devotees do not take up the task of elevating everyone to Kṛṣṇa consciousness, then who will do it? Those who claim to be devotees but do not engage in Kṛṣṇa’s service to elevate all living creatures to Kṛṣṇa consciousness are to be considered kaniṣṭha-adhikārīs (people in the lowest stage of devotional service). When one rises to the second platform of devotional service, his business is to propagate Kṛṣṇa consciousness all over the world. Those who are active in the Kṛṣṇa consciousness movement should not remain in the neophyte stage but should rise to the platform of preachers, the second platform of devotional service. Devotional service is so enchanting that even the first-class devotees (uttama-adhikārīs) also come down to the second platform to preach and render service to the Lord for the benefit of the whole world.