The late date view comes exclusively from external evidence based on a statement made by Irenaeus (A.D. 120-202). Irenaeus is the only source for this late dating of Revelation; all other sources are based on him. There are other early writers whose statements indicate that John wrote Revelation much earlier. Our safest course, therefore, is to study the Revelation itself to see what internal evidence it presents regarding the date of its writing.
The text of Revelation provides a self-witness for the date it was written.
Revelation 11:1-2 (NKJV) Then I was given a reed like a measuring rod. And the angel stood, saying, "Rise and measure the temple of God, the altar, and those who worship there. 2 "But leave out the court which is outside the temple, and do not measure it, for it has been given to the Gentiles. And they will tread the holy city underfoot for forty-two months.
These verses refers to a temple standing in a city called the `holy city'. Based upon Old Testament Scripture, we can surmise that a Christian Jew such as John would have had the historical Jerusalem in mind when he spoke of the holy city.
This reference to the temple must be the historical structure for three reasons. First of all, it was located in Jerusalem.
Secondly, according to Revelation 11:2 it was to be under attack for 42 months. Nero commissioned Flavian Vespasian, a Roman general, to engage Israel in war in February AD 67. He actually entered the Promised Land and engaged in battle that spring so that the Jewish war with Rome lasted from spring AD 67 until the temple fell in August AD 70, forty-two months later. Luke 21:20 contains Jesus' prophecy regarding the destruction of the temple: "But when you see Jerusalem surrounded by armies, then know that its desolation is near." The time from Revelation 11 fits with what history tells us of the Jewish war. Finally, the structure of Revelation 11:1&2 parallels Jesus' statement in His Olivet discourse found in Luke 21:20-24. In Luke 21:5-7 the disciples point to the temple and ask about its future. Jesus tells them it will soon be destroyed, stone by stone. In Luke 21:24 He speaks in terms which are echoed in Revelation 11:2. These two passages speak of the same event, the destruction of Jerusalem.
When was Revelation written? Is the late date view or the early date view correct? We know from historical and archaeological evidence that the temple was destroyed in August of 70 AD. If this temple was still standing when John wrote, he must have written before 70 AD.
Revelation 17 is the second major piece of internal evidence for the early date view of Revelation. In Revelation 17 a vision of the seven-headed beast is recorded. This vision offers clear evidence that Revelation was recorded before the death of Nero Caesar. We know that Nero committed suicide on June 9, 68AD.
Revelation 17:1-6 (NKJV) Then one of the seven angels who had the seven bowls came and talked with me, saying to me, "Come, I will show you the judgment of the great harlot who sits on many waters, 2 "with whom the kings of the earth committed fornication, and the inhabitants of the earth were made drunk with the wine of her fornication." 3 So he carried me away in the Spirit into the wilderness. And I saw a woman sitting on a scarlet beast which was full of names of blasphemy, having seven heads and ten horns. 4 The woman was arrayed in purple and scarlet, and adorned with gold and precious stones and pearls, having in her hand a golden cup full of abominations and the filthiness of her fornication. 5 And on her forehead a name was written: MYSTERY, BABYLON THE GREAT, THE MOTHER OF HARLOTS AND OF THE ABOMINATIONS OF THE EARTH. 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.
Revelation 17:9 (NKJV) "Here is the mind which has wisdom: The seven heads are seven mountains on which the woman sits.
Verses 1, 3, and 6 of Revelation describe a vision and verse nine gives us clues to the meaning of the vision. Almost all scholars recognize that the seven mountains of Revelation 17:9 represent the seven hills of Rome. John points out that the wise one will understand; the recipients of this letter lived under the rule of Rome which was universally distinguished by its seven hills. How could the recipients of this letter who lived in the seven historical churches of Asia minor under Roman imperial rule understand anything else by this geological reference?
Revelation 17:10 (NKJV) "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.
Revelation 17:10 says that the seven heads also represent a political situation: "There are also seven kings." Revelation 17:10 shows how the seven heads also correspond to the line of the Caesars. "Five have fallen", (past tense): The first five Caesars were Julius, Augustus, Tiberius, Caligula, and Claudius. "One is", (present tense): Nero, the sixth Caesar, was on the throne as John was writing the Revelation. Nero reigned from October 54 AD until June 68 AD, when he committed suicide because his empire was in civil war. "And the other has not yet come. And when he comes, he must continue a short time," (Future tense): Galba, the seventh Caesar, reigned for less than 7 months (June, 68 AD to January, 69 AD).
In Revelation 17:7 the angel says, "Don't wonder--I'll show you what it means"; in verses nine and ten the vision is explained. The seven heads refer to a historical place, Rome, and the political scene, Nero's reign. Revelation must have been written before Nero committed suicide in 68 AD. The internal evidence points clearly to the early date view.