Bg. 4.8

परित्राणाय साधूनां विनाशाय च दुष्कृताम् ।
धर्मसंस्थापनार्थाय सम्भवामि युगे युगे ॥८॥

paritrāṇāya sādhūnāṁ
vināśāya ca duṣkṛtām
dharma-saṁsthāpanārthāya
sambhavāmi yuge yuge

paritrāṇāyaplugin-autotooltip__small plugin-autotooltip_bigparitrāṇāya

for the deliverance.—for the deliverance; sādhūnāmplugin-autotooltip__small plugin-autotooltip_bigsādhūnām

and of the devotees; for saintly persons; of devotees; of honest persons; of saintly persons; of the brāhmaṇas, who were all Vaiṣṇava devotees; of the devotees; of the gentle; of the honest; of the honest persons; of the pure devotees also; of the saintly persons; of the saints; of the society of devotees and great sages; who are honest (because we honestly seek elevated social standards and bodily comfort).—of the devotees; vināśāyaplugin-autotooltip__small plugin-autotooltip_bigvinasaya

destroy.—for the annihilation; caplugin-autotooltip__small plugin-autotooltip_bigca

ca; all these; also; also other bodily forms; also that I have not been able to ask; and (the five gross material elements and the ten acting and knowledge-gathering senses); and; and also; and Devahūti; and for all; and the paraphernalia; as also; as much as; as well; as well as; but; certainly; either; however; indeed; only; or; over and above; respectively; the word ca; this word ca; thus; totally; unlimitedly; verily.—also; duṣkṛtāmplugin-autotooltip__small plugin-autotooltip_bigduskrtam

who has committed sinful acts.—of the miscreants; dharmaplugin-autotooltip__small plugin-autotooltip_bigdharma

activities; acts of religion; by Mahārāja Dharma, or Dharmarāja; by their pious activities; characteristic function; characteristic nature; characteristics; characteristics of age; Dharmeyu; duties; duty; factual occupation; for the right cause; in religious activities; in the form of dedication to the husband, etc; My religion; O personality of religion; O personality of religious principles; O Vidura; occupation; occupational duties; occupational duty; of Dharma, the god of piety; of religious life; of religious principles; piety; principle; principles of devotional service; principles of religion; regular activities; religion; religiosity; religious; religious practice; religious principle; religious principles; religious procedures; the character; the duty; the occupation; the occupational duty; the principles; the religion; the religious principles; vow.—principles of religion; saṁsthāpanaplugin-autotooltip__small plugin-autotooltip_bigsaṁsthāpana

for the purpose of establishing; to reestablish.-arthāyaplugin-autotooltip__small plugin-autotooltip_bigarthāya

for any purpose; for increasing one's opulence; for material gain; for self-interest; for the interest of.—to reestablish; sambhavāmiplugin-autotooltip__small plugin-autotooltip_bigsambhavāmi

I appear; I do appear; I do incarnate.—I do appear; yugeplugin-autotooltip__small plugin-autotooltip_bigyuge

after millennium; age; and ages; different periods; millennium; period.—millennium; yugeplugin-autotooltip__small plugin-autotooltip_bigyuge

after millennium; age; and ages; different periods; millennium; period.—after millennium. ¶

In order to deliver the pious and to annihilate the miscreants, as well as to reestablish the principles of religion, I advent Myself millennium after millennium. ¶

According to Bhagavad-gītā, a sādhu (holyman) is a man in Kṛṣṇa consciousness. A person may appear to be irreligious, but if he has the qualifications of Kṛṣṇa consciousness wholly and fully, he is to be understood to be a sādhu. And duṣkṛtam applies to one who doesn’t care for Kṛṣṇa consciousness. Such miscreants, or duṣkṛtam, are described as foolish and the lowest of mankind, even though they may be decorated with mundane education; whereas another person, who is one hundred percent engaged in Kṛṣṇa consciousness, is accepted as sādhu, even though such a person may neither be learned nor well cultured. As far as the atheistic are concerned, it is not necessary for the Supreme Lord to appear as He is to destroy them, as He did with the demons Rāvaṇa and Kaṁsa. The Lord has many agents who are quite competent to vanquish demons. But the Lord especially descends to appease His unalloyed devotees, who are always harassed by the demonic. The demon harasses the devotee, even though the latter may happen to be his kin. Although Prahlāda Mahārāja was the son of Hiraṇyakaśipu, he was nonetheless persecuted by his father; although Devakī, the mother of Kṛṣṇa, was the sister of Kaṁsa, she and her husband Vasudeva were persecuted only because Kṛṣṇa was to be born of them. So Lord Kṛṣṇa appeared primarily to deliver Devakī, rather than kill Kaṁsa, but both were performed simultaneously. Therefore it is said here that to deliver the devotee and vanquish the demon miscreants, the Lord appears in different incarnations. ¶

In the Caitanya-caritāmṛta of Kṛṣṇadāsa Kavirāja, the following verses summarize these principles of incarnation: ¶

sṛṣṭi-hetu yei mūrti prapañce avatare
sei īśvara-mūrti ‘avatāra’ nāma dhare
māyātita paravyome savāra avasthāna
viśve ‘avatāri’ dhare ‘avatāra’ nāma.

“The avatāra, or incarnation of Godhead, descends from the kingdom of God for material manifestation. And the particular form of the Personality of Godhead who so descends is called an incarnation, or avatāra. Such incarnations are situated in the spiritual world, the kingdom of God. When they descend to the material creation, they assume the name avatāra.” ¶

There are various kinds of avatāras, such as puruṣāvatāras, guṇāvatāras, līlāvatāras, śaktyāveśa avatāras, manvantara-avatāras and yugāvatāras—all appearing on schedule all over the universe. But Lord Kṛṣṇa is the primeval Lord, the fountainhead of all avatāras. Lord Śrī Kṛṣṇa descends for the specific purposes of mitigating the anxieties of the pure devotees, who are very anxious to see Him in His original Vṛndāvana pastimes. Therefore, the prime purpose of the Kṛṣṇa avatāra is to satisfy His unalloyed devotees. ¶

The Lord says that He incarnates Himself in every millennium. This indicates that He incarnates also in the age of Kali. As stated in the Śrīmad-Bhāgavatam, the incarnation in the age of Kali is Lord Caitanya Mahaprabhu, who spread the worship of Kṛṣṇa by the saṅkīrtana movement (congregational chanting of the holy names), and spread Kṛṣṇa consciousness throughout India. He predicted that this culture of saṅkīrtana would be broadcast all over the world, from town to town and village to village. Lord Caitanya as the incarnation of Kṛṣṇa, the Personality of Godhead, is described secretly but not directly in the confidential parts of the revealed scriptures, such as the Upaniṣads, Mahābhārata, Bhāgavatam, etc. The devotees of Lord Kṛṣṇa are much attracted by the saṅkīrtana movement of Lord Caitanya. This avatāra of the Lord does not kill the miscreants, but delivers them by the causeless mercy of the Lord. ¶