If the book was written in the final decade of the first century (the traditional view), then its prophecies probably do not concern the destruction of Jerusalem, an event that would have already taken place. On the other hand, if Revelation was written before A.D. 70, then a case could be made that it describes chiefly those events leading up to Jerusalem's fall. R.C. Sproul, The Last Days according to Jesus, p 132.
Note: Amillennialists proclaim that Revelation was written before Jerusalem was destroyed.
The Question of Evidence
When questions of dating biblical books arise, one must consider two main kinds of evidence: external and internal. As the word suggests, external evidence looks to material apart from and outside the book itself, such as the testimony of ancient writers or citations, quotes, or allusions from other writers, and so forth. Page 140.
Note: R.C. Sproul violates his own definition of external versus internal evidence.
Gentry canvasses other internal evidence for an early date of Revelation, such as the question of emperor worship, the role of Jewish Christianity, the looming Jewish war, and the role of Nero. "My confident conviction," concludes Gentry, "is that a solid case for a Neronic date for Revelation can be set forth from the available evidences, both internal and external. Page 149.
Note: Early church fathers gave a late writing of Revelation.
Irenaeous referred to Revelation in a work he wrote near the end of the second century, probably between A.D. 180 and 190. Irenaeus's credibility is enhanced, not only by his important defense of the faith, but also by his claim to be a personal acquaintance of Polycarp, who in turn had known the Apostle John himself. Irenaeus's testimony regarding Revelation is found in book 5 of his famous work Against Heresies. This has been rendered in English as follows: "We will not, however, incur the risk of pronouncing positively as to the name of Antichrist; for if it were necessary that his name should be distinctly revealed in this present time, it would have been announced by him who beheld the apocalyptic vision. For that was seen no very long time since, but almost in our day, towards the end of Domitian's reign." Pages 141-142.
The Identity of the Sixth King
Revelation 17:10 "There are also seven kings. Five have fallen, one is, and the other has not yet come. And when he comes, he must continue a short time."
A more natural approach, however, is to begin the list of kings with Julius Caesar, as was the custom of ancient historians such as Josephus and Suetonius, as well as Dio Cassius. In this series, the sixth king is Nero. If he is the king referred to in Revelation in the present tense, then this adds considerable weight to the argument for dating the book in the mid-to late-sixties. Page 147.
Note: Amillennialists avoid the context of Revelation chapter 17 in that "the women" who temporarily controls the kings kills Christians.
Revelation 17:6 I saw the woman, drunk with the blood of the saints and with the blood of the martyrs of Jesus. And when I saw her, I marveled with great amazement.
Which was the first emperor to persecute Christians? The emperors from Julius Caesar through Claudius never heard of Christians. The first emperor to persecute Christians was Nero to whom Paul appealed his conviction. The five kings who have fallen would be Nero, Galba, Otho, Vitellius, and Vespasian. The emperor "who is" (at time Revelation was written) would be Domitian.
Additionally, Amillennialists forget that both Paul and Jesus sent letters to the church at Ephesus. Paul commends the saints in Ephesus for their great love. (Ephesians 1:15-16) "Therefore I also, after I heard of your faith in the Lord Jesus and your love for all the saints, do not cease to give thanks for you, making mention of you in my prayers:" However, our Lord Jesus Christ rebukes the church in Ephesus for their lack of love. (Revelation 2:4) "Nevertheless I have this against you, that you have left your first love." Since Paul's letter to the Ephesians was written in the early sixties, at least some time must have passed for the church to decline from praise to condemnation.