The actual date that Revelation was written in is critical to its interpretation. The early tradition of the Church along with evidence in the writings of Irenaeus was that it was written in the period of the Emperor Domitian's reign, therefore the events prophesied within it were historically interpreted either allegorically (and thus covering the whole period of church history from the Ascension of Christ to His Return) or yet future. However, of late, a school known as Preterism has asserted that the book itself was written prior to the Fall of Jerusalem and that the events it covers are mostly concerned with the siege and fall of Jerusalem and the Jewish state. A Preterist is someone who believes most or all of the prophecies of Revelation to have been already fulfilled. Partial Preterists believe that the Return of Jesus and the Resurrection is yet future, while full Preterists believe that Jesus returned in 70 AD that the resurrection has already occurred at that we will live forever in heaven not a redeemed earth. They believe this is the completed kingdom age that we are living in.
If on the other hand Jerusalem had already been sacked by the Romans (which would be the case if the book was indeed written after the events of 70 AD) most of the Preterist and partial Preterist positions would be proven fundamentally erroneous.
Evidence for a date somewhere around 90-95 AD:
1) Emperor Worship: The Revelation assumes an active cultus of Emperor Worship (Rev. 13:4, 13:12, 13:15-16, 14:9-11, etc., but the historical evidence is that Emperor worship was discouraged by Nero. However Domitian (81-96AD) clearly regarded himself as a God and demanded Emperor worship from his subects.
2) Written in a time of persecution for the faith: Revelation indicates that the active persecution of Christians had already begun by this time (2:13) and the fact that John himself was already exiled to Patmos (which was something that only a Pro-consul or above could do). There was a Neronic persecution of Christians, but this was specifically because Nero made them scapegoats for the fire that destroyed Rome. We also have the visions of the woman "drunk with the blood of the saints" and this image fits far better with the later organized persecutions that followed the 1st century.
3) The Condition of the Asiatic Churches: Several of the churches appear to indicate a marked deterioration in their spiritual vitality, and a growth of forms of heresy not mentioned in the Epistles of Paul (Nicolationism – Rev. 2:6) These deteriorated churches include Ephesus and Laodicea, which were specifically planted by Paul and which he was still active in the oversight of in the pre-70 AD period. To assume that new heresies unmentioned by Paul could spring up and become well advanced in these churches overnight, seems difficult to believe. Then there is the warning of Paul to the elders of the Ephesian church: For I know this, that after my departure savage wolves will come in among you, not sparing the flock. (Acts 20:29) this would seem to indicate that he knew that in the future, Ephesus would be drawn away by elders teaching wrong doctrine, but does not seem to logically indicate that this had already happened.
