The first coming of Jesus was a humble incarnation to help the people for salvation through their repentance and conversion. His second coming is to separate the good from the evil and to rule the just forever.
Prophet Daniel had the vison of the future coming of Christ in his glory on the clouds. He wrote, “As the visions during the night continued, I saw coming with the clouds of heaven One like a son of man. When he reached the Ancient of Days and was presented before him, He received dominion, splendor, and kingship; all nations, peoples and tongues will serve him. His dominion is an everlasting dominion that shall not pass away, his kingship, one that shall not be destroyed” (Dan 7:13-14).
Jesus predicted his second coming and its purpose. At his Last Supper discourse to the apostles, Jesus said, “In my Father’s house there are many dwelling places. If there were not, would I have told you that I am going to prepare a place for you? And if I go and prepare a place for you, I will come back again and take you to myself, so that where I am you also may be” (Jn 14:2-3). He spoke of his glorious return to reestablish the kingdom in its fullness: “When the Son of Man comes in His glory, and all the angels with Him, He will sit on His glorious throne. All the nations will be gathered before Him, and He will separate the people one from another, as a shepherd separates the sheep from the goats” (Mt 25:31-32).
John the Evangelist, through his vision at Patmos, confirmed the second coming of Christ: “Behold, he is coming amid the clouds, and every eye will see him, even those who pierced him. All the peoples of the earth will lament him. Yes. Amen” (Rev 1:7).
The second coming of Christ is meritorious for the faithful disciples of Jesus. Whereas it will be a hazardous time for the sinners. There will come an unexpected time when we cannot change our eternal destiny. Now is the time for us to do good.