Jesus Christ said to his disciples that the Sign of Son of Man will appear in the sky (Matthew 24:30). Jesus Christ said that the son of Man will come in clouds with great power and glory (Mark 13:26). Jesus Christ said that the Son of Man will come with all the angels with him (Matthew 25:31).
Jesus said that the destruction of Jerusalem and his second coming will happen in the generation of his disciples (Matthew 24, Mark 13, Luke 21) - "This generation shall not pass until all these things happened."
A Generation is 40 years in Bible. Here are some examples.
Numbers 32:13 (ESV) - And the Lord's anger was kindled against Israel, and he made them wander in the wilderness forty years, until all the generation that had done evil in the sight of the Lord was gone.
Deuteronomy 1:34-36 (ESV) - And the Lord heard your words and was angered, and he swore, ‘Not one of these men of this evil generation shall see the good land that I swore to give to your fathers, except Caleb the son of Jephunneh. He shall see it, and to him and to his children I will give the land on which he has trodden, because he has wholly followed the Lord!"
Psalms 95:10 (ESV) - For forty years I loathed that generation and said, “They are a people who go astray in their heart, and they have not known my ways.”
Hebrews 3:9-10 (ESV) - Today, if you hear his voice, do not harden your hearts as in the rebellion, on the day of testing in the wilderness,where your fathers put me to the test and saw my works for forty years. Therefore I was provoked with that generation, and said, ‘They always go astray in their heart; they have not known my ways."
The Israelites wandered 40 years in the wilderness (Ex. 16:35; Deut. 2:7), in which time an entire generation died out (Num. 14:33; 32:13).
Acts 13:36 (ESV) - For David, after he had served the purpose of God in his own generation, fell asleep and was laid with his fathers and saw corruption.
In 2 Samuel 5:4 (ESV)- "David was thirty years old when he began to reign, and he reigned forty years."
We also know that Jerusalem was destroyed within the generation Jesus taught (AD 30-70). So all of the prophecies were fulfilled in that generation.
Right before the fall of Jerusalem in 70 AD, People in Judea saw the chariots and soldiers in their armor running about among the clouds.
This incident in the sky was recorded by Josephus and Tacitus who lived during that period. This was also later recorded by Church Historian Eusebius in his Ecclesiastical History, Latin Document Pseudo Hegesippus, and Jewish History Document called "Sepher Yosippon."
Here are the informations.
Josephus (Jewish Wars)
Jewish War 6:289 (22.214.171.1249) Thus there was a star resembling a sword, which stood over the city, and a comet, that continued a whole year.
Jewish War 6:290 (126.96.36.1990) Thus also, before the Jews’ rebellion, and before those commotions which preceded the war, when the people were come in great crowds to the feast of unleavened bread, on the eighth day of the month Xanthicus [Nisan], and at the ninth hour of the night, so great a light shone round the altar and the holy house, that it appeared to be bright day time; which light lasted for half an hour.
Jewish War 6:291 (188.8.131.521) This light seemed to be a good sign to the unskillful, but was so interpreted by the sacred scribes, as to portend those events that followed immediately upon it.
Jewish War 6:296 (184.108.40.2066) So these publicly declared, that this signal foreshowed the desolation that was coming upon them. Besides these, a few days after that feast, on the twenty-first day of the month Artemisius [Jyar],
Jewish War 6:297 (220.127.116.117) a certain prodigious and incredible phenomenon appeared; I suppose the account of it would seem to be a fable, were it not related by those that saw it,
Jewish War 6:298 (18.104.22.1688) and were not the events that followed it of so considerable a nature as to deserve such signals; for, before sunsetting, chariots and troops of soldiers in their armor were seen
Jewish War 6:299 (22.214.171.1249) running about among the clouds, and surrounding of cities. Moreover at that feast which we call Pentecost, as the priests were going by night into the inner [court of the] temple, as their custom was, to perform their sacred ministrations, they said that, in the first place, they felt a quaking, and heard a great noise,
Jewish War 6:300 (126.96.36.1990) and after that they heard a sound as of a great multitude, saying, "Let us remove hence."
Tacitus, Histories, Book 5
"Prodigies had occurred, which this nation, prone to superstition, but hating all religious rites, did not deem it lawful to expiate by offering and sacrifice. There had been seen hosts joining battle in the skies, the fiery gleam of arms, the temple illuminated by a sudden radiance from the clouds. The doors of the inner shrine were suddenly thrown open, and a voice of more than mortal tone was heard to cry that the Gods were departing. At the same instant there was a mighty stir as of departure. Some few put a fearful meaning on these events, but in most there was a firm persuasion, that in the ancient records of their priests was contained a prediction of how at this very time the East was to grow powerful, and rulers, coming from Judaea, were to acquire universal empire."
Eusebius Ecclesiastical History, Book 3, Chapter 8, Section 4-6
And the eastern gate of the inner temple, which was of bronze and very massive, and which at evening was closed with difficulty by twenty men, and rested upon iron-bound beams, and had bars sunk deep in the ground, was seen at the sixth hour of the night to open of itself.
And not many days after the feast, on the twenty-first of the month Artemisium, (97) a certain marvelous vision was seen which passes belief. The prodigy might seem fabulous were it not related by those who saw it, and were not the calamities which followed deserving of such signs. For before the setting of the sun, chariots and armed troops were seen throughout the whole region in mid-air, wheeling through the clouds and encircling the cities.
And at the feast which is called Pentecost, when the priests entered the temple at night, as was their custom, to perform the services, they said that at first they perceived a movement and a noise, and afterward a voice as of a great multitude, saying, ‘Let us go hence.’
Pseudo-Hegesippus, Chapter 44. (Translated from the Latin by Wade Blocker. This excerpt taken from the Latin edited by Vincente Ussani):
Also after many days a certain figure appeared of tremendous size, which many saw, just as the books of the Jews have disclosed, and before the setting of the sun there were suddenly seen in the clouds chariots and armed battle arrays, by which cities of all Judaea and its territories were invaded. Moreover in the celebration itself of the Pentecost the priests entering the interior of the temple at night time, that they might celebrate the usual sacrifices, assered themselves at first to have a felt a certain movement and a sound given forth, afterwards even to have heard shouted in a sudden voice "we cross over from here."
Sepher Yosippon" is a 10th century historical Jewish document written in Hebrew that mentions about the fall of Jerusalem in 70 AD. Sefer Josippon also mentions about the vision of soldiers and chariots in the sky which we read in Josephus' Jewish Wars, Tacitus's Histories, Eusebius' Ecclesiastical History, and Latin Document "Pseudo Hegesippus."
Sepher Yosippon (A Medieval History of Ancient Israel) translated from the Hebrew by Steven B. Bowman. Excerpts from Chapter 87 "Burning of the Temple"
"Moreover, in those days were seen chariots of fire and horsemen, a great force flying across the sky near to the ground coming against Jerusalem and all the land of Judah, all of them horses of fire and riders of fire. When the holiday of Shavu'oth came in those days, during the night the priests heard within the Temple something like the sound of men going and the sound of men marching in a multitude going into the Temple, and a terrible and mighty voice was heard speaking: "Let's go and leave this House."
People usually ask what does chariots and soldiers in the sky have to do with sign of Son of Man and the Bible.
Here are some examples.
Jeremiah 4:13 (KJV) – "Behold, he shall come up as clouds, and his chariots shall be as a whirlwind: his horses are swifter than eagles. Woe unto us! for we are spoiled."
Isaiah 66:15 (KJV) – "For, behold, the Lord will come with fire, and with his chariots like a whirlwind, to render his anger with fury, and his rebuke with flames of fire."
2 Kings 2:11 (KJV) - And it came to pass, as they still went on, and talked, that, behold, there appeared a chariot of fire, and horses of fire, and parted them both asunder; and Elijah went up by a whirlwind into heaven.
2 Kings 6:17 (KJV) - And Elisha prayed, and said, Lord, I pray thee, open his eyes, that he may see. And the Lord opened the eyes of the young man; and he saw: and, behold, the mountain was full of horses and chariots of fire round about Elisha.
Zachariah 6:1-6 (KJV) - "And I turned, and lifted up mine eyes, and looked, and, behold, there came four chariots out from between two mountains; and the mountains were mountains of brass. In the first chariot were red horses; and in the second chariot black horses; And in the third chariot white horses; and in the fourth chariot grisled and bay horses. Then I answered and said unto the angel that talked with me, What are these, my lord? And the angel answered and said unto me, These are the four spirits of the heavens, which go forth from standing before the Lord of all the earth. The black horses which are therein go forth into the north country; and the white go forth after them; and the grisled go forth toward the south country."
There are other verses in the Bible that involve God and his chariots.
This vision in the sky and the fall of Jerusalem (which includes the destruction of temple) happened between 30 AD - 70 AD (40 years).
Revelation 1:3 (NIV) - "Blessed is the one who reads aloud the words of this prophecy, and blessed are those who hear it and take to heart what is written in it, because the time is near."
We read that the time is near.
Revelation 1:7 (NIV) - "Look, he is coming with the clouds," and "every eye will see him, even those who pierced him"; and all peoples on earth "will mourn because of him." So shall it be! Amen.
We read that every eye will see him even those who pierced him.
Take a notice "He is coming with the clouds" in Revelation 1:7 and read Jeremiah 4:13 (Mentioned above).
The generation of Jews during the time of Jesus was an extremely evil generation. We see Jesus calling them "wicked (or sinful) and adulterous generation." (Matthew 12:39, Matthew 16:4, Mark 8:38, etc.). We also see Jesus calling people in that generation that their father is devil (John 8:44) due to their evil nature. We also see Both Jesus Christ and John the Baptist calling them "offspring of vipers" (Matthew 23, Luke 3).
Jewish Priest Josephus agrees with Jesus on the wickedness of that generation.
"I shall therefore speak my mind here at once briefly: — that neither did any other city suffer such miseries, nor did any age ever breed a generation more fruitful in wickedness than this was, from the beginning of the world." (Jewish Wars V, 10:5).
In Jewish Wars Book Six, Chapter 9, Paragraph 3, we read that 1.1 million people died and 97,000 people were taken as prisoners.
For more information, check this link under Preterism - http://en.metapedia.org/wiki/Second_coming_of_jesus