Although God has given us all facilities to live peacefully on this earth, cultivate Kṛṣṇa consciousness, and finally to come to Him, in this age we’re unfortunate. We are short-lived, and there are so many people without food, shelter, married life or defense from the onslaughts of nature. This is due to the influence of this age of Kali. Therefore Lord Caitanya Mahāprabhu, seeing the dreadful situation in this age, emphasized the absolute necessity for cultivating spiritual life. And how should we do it? Caitanya Mahāprabhu gives the formula:

  harer nāma harer nāma
harer nāmaiva kevalam
kalau nāsty eva nāsty eva
nāsty eva gatir anyathā

  “Just always chant Hare Kṛṣṇa.” Never mind whether you are in a factory or in a hell, in a shack or in a skyscraper—it doesn’t matter. just go on chanting Hare Kṛṣṇa, Hare Kṛṣṇa, Kṛṣṇa Kṛṣṇa, Hare Hare/ Hare Rāma, Hare Rāma, Rāma Rāma, Hare Hare. There is no expense, there is no impediment, there is no caste, there is no creed, there is no color—anyone can do it. just chant and hear.
OWK (p. 69)

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Everywhere in this age of iron everything is degraded, degraded in this sense: prāyeṇālpāyuṣaḥ sabhya kalāv asmin yuge janāḥ (Bhāg. 1.1.10). In this age of Kali the duration of life is diminished, and men are not moved to understand self-realization, and if they are, they are invariably misled by so many deceitful leaders. The age is very corrupt. Therefore Caitanya Mahāprabhu’s process of chanting Hare Kṛṣṇa is the best and the simplest method.

 

  “In this age of Kali there is no other religion than glorifying the Lord by utterance of His holy name, and that is the injunction of all the revealed scriptures. There is no other way, there is no other way, there is no other way.” This verse appears in the Bṛhan-nāradīya Purāṇa. Harer nāma harer nāma harer nāmaiva kevalam. Simply chant Hare Kṛṣṇa. There is no other alternative. Kalau nāsty eva nāsty eva nāsty eva gatir anyathā. In this age, Kali, there is no other alternative for self-realization. So we have to accept it.

  There is another similar verse in the Śrīmad-Bhāgavatam. In the Twelfth Canto, Third Chapter, Parīkṣit Mahārāja was informed by Śukadeva Gosvāmī of the faults of this age, and now all the symptoms of the age of Kali are apparent. In the conclusive portion, however, Śukadeva Gosvāmī said, kaler doṣa-nidhe rājann asti hy eko mahān guṇaḥ: “My dear king, this age, Kali, is full of faulty things, but there is one good opportunity.” What is that? Kīrtanād eva kṛṣṇasya mukta-saṅgaḥ paraṁ vrajet: “Simply by chanting this Hare Kṛṣṇa mantra one can become liberated and go back to Godhead.”
SSR (pp. 154-155

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Chanting of the holy name of the Lord is the common platform for the universal religion of mankind in the Kali-yuga.

In this present age quarrels take place even over trifles, and therefore the śāstras have recommended for this age a common platform for realization, namely chanting the holy names of the Lord. People can hold meetings to glorify the Lord in their respective languages and with melodious songs, and if such performances are executed in an offenseless manner, it is certain that the participants will gradually attain spiritual perfection without having to undergo more rigorous methods. At such meetings everyone, the learned and the foolish, the rich and the poor, the Hindus and the Muslims, the Englishmen and the Indians, and the caṇḍālas and the brāhmaṇas, can all hear the transcendental sounds and thus cleanse the dust of material association from the mirror of the heart. To confirm the Lord's mission, all the people of the world will accept the holy name of the Lord as the common platform for the universal religion of mankind.
SB. 1, Intro. (1:1, p.7)

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The Hare Krsna mantra is espacially suitted to deliver us from the dangers of the Kali-yuga.

Only the dvijas (the brāhmaṇas) and the devas (the demigods) can be delivered from material existence by the instructions of the Supreme Personality of Godhead. Whatever is spoken by the Supreme Personality of Godhead is a mantra and is suitable for delivering the conditioned souls from mental speculation. The conditioned souls are engaged in a struggle for existence (manaḥ ṣaṣṭhānīndriyāṇi prakṛti-sthāni karṣati [Bg. 15.7]). Deliverance from this struggle constitutes the highest benefit, but unless one gets a mantra from the Supreme Personality of Godhead, deliverance is impossible. The beginning mantra is the Gāyatrī mantra. Therefore, after purification, when one is qualified to become a brāhmaṇa (dvija), he is offered the Gāyatrī mantra. Simply by chanting the Gāyatrī mantra, one can be delivered. This mantra, however, is suitable only for the brāhmaṇas and demigods. In Kali-yuga, we are all in a very difficult position, in which we need a suitable mantra that can deliver us from the dangers of this age. Therefore the Supreme Personality of Godhead, in His incarnation as Lord Caitanya, gives us the Hare Kṛṣṇa mantra.

  “In this age of quarrel and hypocrisy the only means of deliverance is chanting the holy name of the Lord. There is no other way. There is no other way. There is no other way.” In His Śikṣāṣṭaka, Lord Caitanya says, paraṁ vijayate śrī-kṛṣṇa-saṅkīrtanam: “All glories to the chanting of śrī-kṛṣṇa-saṅkīrtana!” The mahā-mantra—Hare Kṛṣṇa, Hare Kṛṣṇa, Kṛṣṇa Kṛṣṇa, Hare Hare/ Hare Rāma, Hare Rāma, Rāma Rāma, Hare Hare—is directly chanted by the Lord Himself, who gives us this mantra for deliverance.

  We cannot invent any means to be delivered from the dangers of material existence. Here, even the demigods, such as Lord Brahmā and Lord Śiva, and the prajāpatis, such as Dakṣa, are said to be like illuminating sparks in the presence of the Supreme Lord, who is compared to a great fire. Sparks are beautiful as long as they are in the fire. Similarly, we have to remain in the association of the Supreme Personality of Godhead and always engage in devotional service, for then we shall always be brilliant and illuminating. As soon as we fall from the service of the Lord, our brilliance and illumination will immediately be extinguished, or at least stopped for some time. When we living entities, who are like sparks of the original fire, the Supreme Lord, fall into a material condition, we must take the mantra from the Supreme Personality of Godhead as it is offered by Śrī Caitanya Mahāprabhu. By chanting this Hare Kṛṣṇa mantra, we shall be delivered from all the difficulties of this material world.
SB. 8.6.15