SB 11.7.4

yarhy evāyaṁ mayā tyakto
 loko ’yaṁ naṣṭa-maṅgalaḥ
bhaviṣyaty acirāt sādho
 kalināpi nirākṛtaḥ
Synonyms: 
yarhi — when; eva — certainly; ayam — this; mayā — by Me; tyaktaḥ — abandoned; lokaḥ — the world; ayam — this; naṣṭa-maṅgalaḥ — bereft of all auspiciousness or piety; bhaviṣyati — it will be; acirāt — very soon; sādho — O saintly one; kalinā — due to Kali; api — himself; nirākṛtaḥ — overwhelmed.
Translation: 
O saintly Uddhava, in the near future I will abandon this earth. Then, being overwhelmed by the Age of Kali, the earth will be bereft of all piety.
Purport: 

Lord Kṛṣṇa’s plan was to bring Uddhava back to His own eternal abode after a brief delay. Because of Uddhava’s extraordinary spiritual qualities, the Lord wanted to engage him in propagating His message among other saintly persons who were not yet advanced to the stage of pure devotional service. However, the Lord assured Uddhava that he would not be bereft of the Lord’s association for even a moment. Also, because Uddhava had become a perfect master of his senses, he would never be afflicted by the three modes of material nature. In this way, before bringing Uddhava back home, back to Godhead, the Lord empowered him to carry out a specific confidential mission.

Wherever the supreme position of the Personality of Godhead is not recognized, useless mental speculation becomes very prominent, and the safe and sure path of hearing perfect Vedic knowledge becomes covered by the chaos of mental concoction. At the present time, especially in the Western countries, literally millions of books are being published on hundreds and thousands of subjects; yet despite this proliferation of mental concoction people remain totally in ignorance about the most fundamental issues of human life, namely, Who am I? Where have I come from? Where am I going? What is my soul? What is God?

The Personality of Godhead, Lord Śrī Kṛṣṇa, is the reservoir of innumerable enchanting pastimes, and thus He is the source of innumerable varieties of pleasure. In fact, He is the ocean of eternal pleasure. When the eternal soul is bereft of the constitutional pleasure that comes from loving service to the Lord, he is overwhelmed and bewildered by material nature. He helplessly chases after material sense gratification, thinking that one material object is good and another bad, and constantly changes his assessment of what is good and what is bad. Thus he derives no peace or pleasure, is in constant anxiety and is repeatedly thrashed by the cruel laws of nature in the form of birth, death, old age and disease.

In this way the conditioned soul becomes a fit candidate to take birth in Kali-yuga, which is the epitome of misfortune. In Kali-yuga the living entities, who are already suffering so many tribulations, mercilessly turn against one another. Human society in Kali-yuga becomes savagely violent, and men open slaughterhouses to butcher hundreds of millions of innocent creatures. Large-scale wars are declared, and millions of human beings, even women and children, are quickly annihilated.

Unless the living entity recognizes the authority of the Personality of Godhead, he remains a helpless victim in the clutches of māyā, or material illusion. He concocts different solutions to release himself from māyā, but these solutions are themselves creations of māyā and thus cannot possibly release the conditioned soul. In fact, they only intensify his distress. In the next verse, Lord Kṛṣṇa specifically warns Uddhava to avoid Kali-yuga and go back home, back to Godhead. Those of us who have already taken birth in Kali-yuga should also heed this advice and immediately take all necessary steps to go back to the Lord’s eternal abode for a blissful life of perfect knowledge. The material world is never a happy place, especially during the fearful days of Kali-yuga.