Douglas F. Kelly's Third "Indicator" for Revelation's Early Date

The assumption of most readers today is that most of Jesus' predictions in the Olivet Discourse are still in our future. This is assumed despite the explicit time indicator in the text stating that the events would transpire within the lifespan of the generation to whom Jesus was preaching. In his commentary on Revelation, Douglas Kelly rightly connects the events of Revelation with the events of the Olivet Discourse. In fact, some scholars like Ken Gentry (in his lectures on Revelation) have posited that the book of Revelation is John's version of the Olivet Discourse. John does not include the Olivet Discourse in his Gospel perhaps because those events are the subject of the entire Apocalypse. That the events of the Olivet Discourse would be fulfilled within "this generation" is Kelly's third "indicator" that points to Revelation's early composition, before the Temple destruction in 70 AD:

Thirdly, in Matthew 23:36 and 24:34, it says 'this generation shall not pass until all these things be fulfilled.' He talks about the destruction of the temple, and the great disaster among the Jewish nation, so that the Lord coming in this generation means that the people who were alive when Jesus was speaking, around 33 AD, would experience it themselves. In other words, before that generation had died a natural death, the Lord would have come in great judgment on his enemies, but also in great mercy on his people. Certainly, there will be a final and ultimate coming of Christ on the last day (and Revelation speaks of it clearly), but we do not need to read the coming of the last day into every mention of his coming in judgment during the lifetime of this generation.

Kelly does well to connect the Olivet Discourse events and Revelation's events and helps us properly differentiate the "coming" of Jesus in 70 AD from the consummation of all things.

Kelly, Douglas. Revelation: A Mentor Expository Commentary. Ross-shire, Scotland: Mentor, 2012. p. 20.