True Christian doctrine comes from the words of Christ. Jesus spoke of the future. Look carefully at the events of history after Jesus ascended. And compare to what John wrote in Revelation.

1. End Times Doctrine
Lives of the Apostles: St. John

2. Where is John?
How the Apostles died.

3. When the apostles made a division of the provinces among them after our Savior's ascension into heaven, in order to
spread the doctrine of their Lord and Master, that of Asia fell to the share of St. John, though he did not immediately enter
upon his charge, but continued at Jerusalem until the death of the blessed Virgin, which happened about fifteen years after
our Lord's ascension.
After being thus released from the trust committed to his care by his dying Master, he went into Asia, and industriously
applied himself to the propagation of Christianity, preaching where the gospel had not then been known, and confirming it
where it was already planted. Many churches of note and eminence were founded by him, particularly those of Smyrna,
Philadelphia, Laodicea, and others; but his chief place of residence was at Ephesus where St. Paul had founded a church,
and had appointed Timothy its pastor.
After John had spent several years in Ephesus, an accusation was laid against him before the emperor Domitian (who had
begun a persecution against the Christians) as being an asserter of false doctrine and impiety, and a public subverter of the
religion of the empire. In consequence of this, and in conformity to the orders of Domitian, the pro-consul of Ephesus sent
him bound to Rome, where he met with that treatment which might have been expected from so barbarous an emperor,
being thrown into a caldron of boiling oil. But the Almighty, who reserved him for further service in the vineyard of his Son,
restrained the heat and delivered him from this seemingly certain destruction. One would have thought that so miraculous
a deliverance might have been enough to have persuaded any rational man that the religion that John taught was from God,
and that he was protected by danger by the hand of Omnipotence. But miracles were not sufficient to convince this cruel
emperor or reduce his fury. He ordered St. John to be transported to a desolate island in the Archipelago called Patmos,
where he lived several years, instructing the poor inhabitants in the knowledge of the Christian faith; and here, near the
end of Domitian's reign, he wrote the book of Revelation (How do we know this?) , exhibiting, by visions and prophetical
representations, the state and condition of Christianity that would take place in the future periods and ages of the church.
On the death of Domitian and the succession of Narva (who repealed all the odious acts of his predecessors, and by public
edicts recalled those whom the fury of Domitian had banished), St. John returned to Asia, and again fixed his residence at
Ephesus, because Timothy, its pastor, had some time before been put to death by the people of that city. Here, with the
assistance of seven other bishops or pastors, he took upon himself the large diocese of Asia Minor, spending his time in an
untiring execution of his charge, traveling from one part to another, and instructing the people in the principles of that holy
religion he was sent to propagate. In this manner John continued to occupy himself till death put a stop to his labors, which
happened in the beginning of the reign of emperor Trajan.
His remains were deposited in the city of Ephesus, where several of the fathers observe that his tomb, in their time, was
remaining in a church, which was built in his honor and called by his name. He was the only apostle who escaped a violent
death. Nevertheless, he is deemed a martyr on account of his having undergone the attempt of an execution, though it did
not take effect. He lived the longest of any of the apostles, being nearly a hundred years old when he died.
http://www.christianity.com/church/church-history/timeline/1-300/st-john-the-evangelist-11629588.html

4. St. John wrote Revelation from Patmos
I, John, your brother and companion in the suffering and kingdom and patient endurance that are ours in Jesus,
was on the island of Patmos because of the word of God and the testimony of Jesus. - Revelation 1:9
But WHEN, exactly?
In 70AD, the Temple was destroyed, as Jesus foretold. It has never been rebuilt.
Luke 21:5,6
Some of his disciples were remarking about how the temple was adorned with beautiful stones and with gifts
dedicated to God. But Jesus said, “As for what you see here, the time will come when not one stone will be left
on another; every one of them will be thrown down.”
Certainly, John would have heard the news. Why then did he write about the Temple?
I was given a reed like a measuring rod and was told, “Go and measure the temple of God and the altar, with its
worshipers. But exclude the outer court; do not measure it, because it has been given to the Gentiles. They will
trample on the holy city for 42 months.” - Revelation 11:1-2
The Temple was destroyed in summer of 70 AD. 42 months earlier, 67AD, Vespasian invaded Galilee.
https://en.wikipedia.org/wiki/First_Jewish%E2%80%93Roman_War
Also, if the kings are Roman rulers, the timeline is clearly earlier than Domitian’s reign, as the 12th ruler.
Revelation 17:9-11
“This calls for a mind with wisdom. The seven heads are seven hills on which the woman sits. They are also seven
kings. Five have fallen, one is, the other has not yet come; but when he does come, he must remain for only a
little while. The beast who once was, and now is not, is an eighth king. He belongs to the seven and is going to
his destruction.
According to the enumeration found in Josephus' Antiquities (18:2:2,6,10) and Suetonius' Lives of the Twelve
Caesars, Nero is Rome's sixth emperor, following Julius Caesar, Augustus, Tiberius, Gaius, and Claudius. The next
reigning emperor, Galba, reigned but six months, the shortest reigning emperor until that time. '
http://www.kennethgentry.com/Merchant2/apocalypse.htm

5. When was Revelation written?
Since Revelation, for many years, had been claimed to have been written
around AD90-95, one might wonder why any of it's verses might have even
some application to the events of AD64-70, however, the late date for
Revelation has now been greatly revised, especially from the extensive
studies of J.A.T. Robinson onwards. It now seems far more likely that
Revelation was written around AD62-66. It had been thought that Revelation
was written during the reign of Domitian (81-96), but the reign of Nero (54-
68) now has very strong advocacy.
As Dr Kenneth Gentry has written, 'There are suggestive evidences within the
book to date it in the mid- to late-60s of the first century.
In fact, the evidence is persuasive enough that it convinced such notable
scholars Moses Stuart, F. J. A. Hort, B. F. Westcott, and F. W. Farrar in the last
century, and J. A. T. Robinson, R. A. Torrey, Albert A. Bell, and C. F. D. Moule in
our own day.
http://www.ukapologetics.net/09/2AD70.printer.htm

6. 12 Roman rulers
#1: 100BC-44BC: Julius Caesar “Roman Republic Imperator. The first deified Roman ruler.”
#2: 27BC-14AD: Augustus Caesar "The first Roman Emperor"
#3: 14AD-37AD: Tiberius "The Emperor who trusted Sejanus and lived in Capri”
#4: 37-41AD: Caligula "The Evil Emperor who proclaimed himself a god"
#5: 41-54AD: Claudius "The bumbling Emperor who married the infamous Messalina”
#6: 54-68AD: Nero "The mad tyrant who blamed the Christians for the burning of Rome"
#7: 68-69AD: Galba "The old man the first in the Year of the four Emperors”
#8: 69AD: Otho "The greedy ruler who lasted just three months”
#9: 69AD: Vitellius "The man who killed his dissolute son”
#10: 69-79AD: Vespasian "The Emperor who built the Colosseum”
#11: 79-81AD: Titus "The Emperor who destroyed the temple in Jerusalem”
#12: 81-96AD: Domitian "The evil emperor who murdered thousands of Christians"
http://www.tribunesandtriumphs.org/roman-empire/timeline-of-roman-emperors.htm

7. How to Divorce Judaism from the Church?
• With the coming of the New Covenant, did
God want the remnants of the Old Covenant
to continue existing in parallel?
• Put another way, when a man divorces his
adulterous, self-righteous, manipulating wife,
and marries a humble woman he truly loves,
does he want to keep around remnants of his
first marriage?
Answer: To divorce Judaism, God allowed the
total destruction of the Temple and Jerusalem.

8. What’s the Point of all this History?
Some of his disciples were remarking about how the temple was adorned with beautiful stones and with gifts dedicated to
God. But Jesus said, “As for what you see here, the time will come when not one stone will be left on another; every one of
them will be thrown down.”
“Teacher,” they asked, “when will these things happen? And what will be the sign that they are about to take place?”
He replied: “Watch out that you are not deceived. For many will come in my name, claiming, ‘I am he,’ and, ‘The time is near.’
Do not follow them. When you hear of wars and uprisings, do not be frightened. These things must happen first, but the end
will not come right away.”
Then he said to them: “Nation will rise against nation, and kingdom against kingdom. There will be great earthquakes,
famines and pestilences in various places, and fearful events and great signs from heaven.
“But before all this, they will seize you and persecute you. They will hand you over to synagogues and put you in prison, and
you will be brought before kings and governors, and all on account of my name. And so you will bear testimony to me. But
make up your mind not to worry beforehand how you will defend yourselves. For I will give you words and wisdom that none
of your adversaries will be able to resist or contradict. You will be betrayed even by parents, brothers and sisters, relatives and
friends, and they will put some of you to death. Everyone will hate you because of me. But not a hair of your head will perish.
Stand firm, and you will win life.
“When you see Jerusalem being surrounded by armies, you will know that its desolation is near. Then let those who are in
Judea flee to the mountains, let those in the city get out, and let those in the country not enter the city. For this is the time of
punishment in fulfillment of all that has been written. How dreadful it will be in those days for pregnant women and nursing
mothers! There will be great distress in the land and wrath against this people. They will fall by the sword and will be taken as
prisoners to all the nations. Jerusalem will be trampled on by the Gentiles until the times of the Gentiles are fulfilled.
“There will be signs in the sun, moon and stars. On the earth, nations will be in anguish and perplexity at the roaring and
tossing of the sea. People will faint from terror, apprehensive of what is coming on the world, for the heavenly bodies will be
shaken. At that time they will see the Son of Man coming in a cloud with power and great glory. When these things begin to
take place, stand up and lift up your heads, because your redemption is drawing near.”
He told them this parable: “Look at the fig tree and all the trees. When they sprout leaves, you can see for yourselves and
know that summer is near. 31 Even so, when you see these things happening, you know that the kingdom of God is near.
“Truly I tell you, this generation will certainly not pass away until all these things have happened.
-Jesus (Luke 21:5-32)
Jesus was talking about the future of the Apostles, but not our future.