SB 2.4.18

kirāta-hūṇāndhra-pulinda-pulkaśā
 ābhīra-śumbhā yavanāḥ khasādayaḥ
ye ’nye ca pāpā yad-apāśrayāśrayāḥ
 śudhyanti tasmai prabhaviṣṇave namaḥ
Word for word: 
kirāta — a province of old Bhārata; hūṇa — part of Germany and Russia; āndhra — a province of southern India; pulinda — the Greeks; pulkaśāḥ — another province; ābhīra — part of old Sind; śumbhāḥ — another province; yavanāḥ — the Turks; khasa-ādayaḥ — the Mongolian province; ye — even those; anye — others; ca — also; pāpāḥ — addicted to sinful acts; yat — whose; apāśraya-āśrayāḥ — having taken shelter of the devotees of the Lord; śudhyanti — at once purified; tasmai — unto Him; prabhaviṣṇave — unto the powerful Viṣṇu; namaḥ — my respectful obeisances.
Translation: 
Kirāta, Hūṇa, Āndhra, Pulinda, Pulkaśa, Ābhīra, Śumbha, Yavana, members of the Khasa races and even others addicted to sinful acts can be purified by taking shelter of the devotees of the Lord, due to His being the supreme power. I beg to offer my respectful obeisances unto Him.
Purport: 

Kirāta: A province of old Bhārata-varṣa mentioned in the Bhīṣma-parva of Mahābhārata. Generally the Kirātas are known as the aboriginal tribes of India, and in modern days the Santal Parganas in Bihar and Chota Nagpur might comprise the old province named Kirāta.

Hūṇa: The area of East Germany and part of Russia is known as the province of the Hūṇas. Accordingly, sometimes a kind of hill tribe is known as the Hūṇas.

Āndhra: A province in southern India mentioned in the Bhīṣma-parva of Mahābhārata. It is still extant under the same name.

Pulinda: It is mentioned in the Mahābhārata (Ādi-parva 174.38), viz., the inhabitants of the province of the name Pulinda. This country was conquered by Bhīmasena and Sahadeva. The Greeks are known as Pulindas, and it is mentioned in the Vana-parva of Mahābhārata that the non-Vedic race of this part of the world would rule over the world. This Pulinda province was also one of the provinces of Bhārata, and the inhabitants were classified amongst the kṣatriya kings. But later on, due to their giving up the brahminical culture, they were mentioned as mlecchas (just as those who are not followers of the Islamic culture are called kafirs and those who are not followers of the Christian culture are called heathens).

Ābhīra: This name also appears in the Mahābhārata, both in the Sabhā-parva and Bhīṣma-parva. It is mentioned that this province was situated on the River Sarasvatī in Sind. The modern Sind province formerly extended on the other side of the Arabian Sea, and all the inhabitants of that province were known as the Ābhīras. They were under the domination of Mahārāja Yudhiṣṭhira, and according to the statements of Mārkaṇḍeya the mlecchas of this part of the world would also rule over Bhārata. Later on this proved to be true, as in the case of the Pulindas. On behalf of the Pulindas, Alexander the Great conquered India, and on behalf of the Ābhīras, Muhammad Ghori conquered India. These Ābhīras were also formerly kṣatriyas within the brahminical culture, but they gave up the connection. The kṣatriyas who were afraid of Paraśurāma and had hidden themselves in the Caucasian hilly regions later on became known as the Ābhīras, and the place they inhabited was known as Ābhīradeśa.

Śumbhas or Kaṅkas: The inhabitants of the Kaṅka province of old Bhārata, mentioned in the Mahābhārata.

Yavanas: Yavana was the name of one of the sons of Mahārāja Yayāti who was given the part of the world known as Turkey to rule. Therefore the Turks are Yavanas due to being descendants of Mahārāja Yavana. The Yavanas were therefore kṣatriyas, and later on, by giving up the brahminical culture, they became mleccha-yavanas. Descriptions of the Yavanas are in the Mahābhārata (Ādi-parva 85.34). Another prince, called Turvasu, was also known as Yavana, and his country was conquered by Sahadeva, one of the Pāṇḍavas. The western Yavana joined with Duryodhana in the Battle of Kurukṣetra under the pressure of Karṇa. It was also foretold that these Yavanas also would conquer India, and it proved to be true.

Khasa: The inhabitants of the Khasadeśa are mentioned in the Mahābhārata (Droṇa-parva). Those who have a stunted growth of hair on the upper lip are generally called Khasas. As such, the Khasa are the Mongolians, the Chinese and others who are so designated.

The above-mentioned historical names are different nations of the world. Even those who are constantly engaged in sinful acts are all corrigible to the standard of perfect human beings if they take shelter of the devotees of the Lord. Jesus Christ and Muhammad, two powerful devotees of the Lord, have done tremendous service on behalf of the Lord on the surface of the globe. And from the version of Śrīla Śukadeva Gosvāmī it appears that instead of running a godless civilization in the present context of the world situation, if the leadership of world affairs is entrusted to the devotees of the Lord, for which a worldwide organization under the name and style of the International Society for Krishna Consciousness has already been started, then by the grace of the Almighty Lord there can be a thorough change of heart in human beings all over the world because the devotees of the Lord are able authorities to effect such a change by purifying the dust-worn minds of the people in general. The politicians of the world may remain in their respective positions because the pure devotees of the Lord are not interested in political leadership or diplomatic implications. The devotees are interested only in seeing that the people in general are not misguided by political propaganda and that the valuable life of a human being is not spoiled in following a type of civilization which is ultimately doomed. If the politicians, therefore, would be guided by the good counsel of the devotees, then certainly there would be a great change in the world situation by the purifying propaganda of the devotees, as shown by Lord Caitanya. As Śukadeva Gosvāmī began his prayer by discussing the word yat-kīrtanam, so also Lord Caitanya recommended that simply by glorifying the Lord’s holy name, a tremendous change of heart can take place by which the complete misunderstanding between the human nations created by politicians can at once be extinguished. And after the extinction of the fire of misunderstanding, other profits will follow. The destination is to go back home, back to Godhead, as we have several times discussed in these pages.

According to the cult of devotion, generally known as the Vaiṣṇava cult, there is no bar against anyone’s advancing in the matter of God realization. A Vaiṣṇava is powerful enough to turn into a Vaiṣṇava even the Kirāta, etc., as above mentioned. In the Bhagavad-gītā (9.32) it is said by the Lord that there is no bar to becoming a devotee of the Lord (even for those who are lowborn, or women, śūdras or vaiśyas), and by becoming a devotee everyone is eligible to return home, back to Godhead. The only qualification is that one take shelter of a pure devotee of the Lord who has thorough knowledge in the transcendental science of Kṛṣṇa (Bhagavad-gītā and Śrīmad-Bhāgavatam). Anyone from any part of the world who becomes well conversant in the science of Kṛṣṇa becomes a pure devotee and a spiritual master for the general mass of people and may reclaim them by purification of heart. Though a person be even the most sinful man, he can at once be purified by systematic contact with a pure Vaiṣṇava. A Vaiṣṇava, therefore, can accept a bona fide disciple from any part of the world without any consideration of caste and creed and promote him by regulative principles to the status of a pure Vaiṣṇava, who is transcendental to brahminical culture. The system of caste, or varṇāśrama-dharma, is no longer regular even amongst the so-called followers of the system. Nor is it now possible to reestablish the institutional function in the present context of social, political and economic revolution. Without any reference to the particular custom of a country, one can be accepted to the Vaiṣṇava cult spiritually, and there is no hindrance in the transcendental process. So by the order of Lord Śrī Caitanya Mahāprabhu, the cult of Śrīmad-Bhāgavatam or the Bhagavad-gītā can be preached all over the world, reclaiming all persons willing to accept the transcendental cult. Such cultural propaganda by the devotees will certainly be accepted by all persons who are reasonable and inquisitive, without any particular bias for the custom of the country. The Vaiṣṇava never accepts another Vaiṣṇava on the basis of birthright, just as he never thinks of the Deity of the Lord in a temple as an idol. And to remove all doubts in this connection, Śrīla Śukadeva Gosvāmī has invoked the blessings of the Lord, who is all-powerful (prabhaviṣṇave namaḥ). As the all-powerful Lord accepts the humble service of His devotee in devotional activities of the arcana, His form as the worshipable Deity in the temple, similarly the body of a pure Vaiṣṇava changes transcendentally at once when he gives himself up to the service of the Lord and is trained by a qualified Vaiṣṇava. The injunction of Vaiṣṇava regulation in this connection runs as follows: arcye viṣṇau śilā-dhīr guruṣu nara-matir vaiṣṇave jāti-buddhiḥ śrī-viṣṇor nāmni śabda-sāmānya-buddhiḥ, etc. “One should not consider the Deity of the Lord as worshiped in the temple to be an idol, nor should one consider the authorized spiritual master an ordinary man. Nor should one consider a pure Vaiṣṇava to belong to a particular caste, etc.” (Padma Purāṇa)

The conclusion is that the Lord, being all-powerful, can, under any and every circumstance, accept anyone from any part of the world, either personally or through His bona fide manifestation as the spiritual master. Lord Caitanya accepted many devotees from communities other than the varṇāśramites, and He Himself declared, to teach us, that He does not belong to any caste or social order of life, but that He is the eternal servant of the servant of the Lord who maintains the damsels of Vṛndāvana (Lord Kṛṣṇa). That is the way of self-realization.