² Behold, he comes with clouds. Heaven appears to our spiritual eye as in a mist or in clouds — so, his coming is on the clouds of heaven, within the hearts of purified believers — just like he ascended: he was taken up, and a cloud received him out of their sight. Acts 1:9. Even Daniel in 538 BC saw Jesus coming on the clouds of heaven: I saw in the night visions, and, behold, one like the Son of man came with the clouds of heaven, and came to the Ancient of days, and they brought him near before him. Dan 7:13. See Howgill's testimony of the Lord's coming to a men purified in this life, and those who die still in their sins.

every eye will see him, and also those who pierced him; and all kindreds of the earth will wail because of him. Each time you sin, you are piercing Christ within you. If you have sorrow and regret, with resolve to not repeat the same mistake again, you have godly sorrow. From the Word of the Lord within: "your godly sorrow is a soothing balm to the wounds you have inflicted on me."

He said: For the Son of man will come in the glory of his Father with his angels;
and then he will reward every man according to his works. (Not just a particular generation.)
Some standing here will not taste death till they see the Son of Man coming in His kingdom. Mat 16:27-8,Mar 8:38,9:1,Luk 9:26-27
Those not purified, to see Jesus' coming in them before death, see him as they die, as all peoples, all nations, all generations do.
Behold, he comes with clouds; and every eye will see him, and they also which pierced him: (also, the Jews 2000 years ago)
and all kindreds of the earth will wail because of him. Even so, Amen. Rev 1:7.
2000 years ago, to the Jewish High Priest and the Pharisees at his trial, Jesus said..
you will see the Son of Man sitting at the right hand of the Power, and coming on the clouds of heaven.  Mark 14:62
This is not a particular generation in our time or later. (See Howgill for more on those not purified).

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