Matthew 16:28 (NASB):
28 “Truly I say to you, there are some of those who are standing here who will not taste death until they see the Son of Man coming in His kingdom.”
And then John, on Patmos, is shown an outstanding vision:
11 And I saw heaven opened, and behold, a white horse, and He who sat on it is called Faithful and True, and in righteousness He judges and wages war. 12 His eyes are a flame of fire, and on His head are many crowns; and He has a name written on Him which no one knows except Himself. 13 He is clothed with a robe dipped in blood, and His name is called The Word of God. 14 And the armies which are in heaven, clothed in fine linen, white and clean, were following Him on white horses. 15 From His mouth comes a sharp sword, so that with it He may strike down the nations, and He will rule them with a rod of iron; and He treads the wine press of the fierce wrath of God, the Almighty. 16 And on His robe and on His thigh He has a name written: “KING OF KINGS, AND LORD OF LORDS.”
17 Then I saw an angel standing in the sun, and he cried out with a loud voice, saying to all the birds that fly in midheaven, “Come, assemble for the great feast of God, 18 so that you may eat the flesh of kings and the flesh of commanders, the flesh of mighty men, the flesh of horses and of those who sit on them, and the flesh of all people, both free and slaves, and small and great.”
19 And I saw the beast and the kings of the earth and their armies, assembled to make war against Him who sat on the horse, and against His army.
[Revelation 19:11-19 NASB]
Was John shown in a vision the second coming of Christ, while he was on Patmos, alive, not having tasted death yet, in fulfillment of the promise made in Matthew 16:28?