The age of discord, quarrels, hypocrisy, indifference, decadence, and sin began 5,000 years ago. This age, rife with conflict, ignorance, irreligion, and vice, where virtue has virtually vanished, lasted 432,000 years.
During this age, immorality grew to such an extent that, finally, the Supreme Lord appeared in person, in the form of Avatar Kalki, to vanquish the demonic beings, save his devotees, restore spirituality, and usher in a new age—the golden age, the age of virtue, purity, and truth. Then the cycle began again.
When Lord Kalki has ushered in the next golden age, the age of virtue, purity, and truth, and delivered the earth and all that remains of civilization from the effects of the dark age, he will return to his eternal abode with his entire entourage and celestial army.
After Lord Kalki's return to his eternal abode, when the surviving beings of the Kali Age have been enlightened and spiritually transformed, the era will change overnight. The minds of all people will become illuminated, and with inevitable force, the golden age, the age of virtue, purity, and truth will begin.
Living beings will then realize their true identity as spiritual souls. Each of them will consciously know themselves to be a spiritual entity.
They will acquire piety, devotion, tranquility, and clear awareness.
Then the perfect beings, the accomplished, enlightened, and perfected devotees who had remained on an Edenic planet in the upper region of the galaxy until the end of the Dark Age, return to Earth and act openly once more. They join the seven sages who have also returned, and together they instruct everyone on spiritual life, Vedic knowledge (the Vedas, the original sacred scriptures), and the progressive organization of society, the re-establishment of the four social and spiritual classes, for a peaceful and fulfilling existence.
Thus, human beings flourish and perform sacred rites, and the sages remain in authority to continue the advancement of the new golden age, the age of virtue, purity, and truth. All beings then walk with Krishna, God, the Supreme Person, finding joy in surrendering to Him and serving Him with love and devotion.