I'm about halfway through my OmniOutliner document of notes made while reading TGD now....
There's a paraphrase in TGD saying that if the epistles of Saint John the Apostle represent John on pot, then the book of Revelation is "John on acid". What makes this observation more interesting is that it may be literally true - or at least closer to the mark than the quip may at first appear.
There was a documentary by Tony Robinson on Revelation and the End of Days, called The Doomsday Code. The - frankly worrying - sentiments of some of the extreme christian right in America are the same as described in TGD; namely that the Middle East instability [inclusive] or global warming or the 2005 hurricane season herald the proximity of the rapture, and that rather than doing anything to help those caught up in these situations we should be actively encouraging the Apocalypse, and xtians should let their heathen friends know that, well, they told us so. In the course of describing modern End Timers, the documentary showed us where Revelation was penned.
There are tens of apocalyptic visions penned by post-Christ Jewish theologians, but only one has been included in what is now termed the canon of the New Testament. That book of the revelation of Jesus Christ to his disciple, John (which isn't accepted by the Eastern Orthodox as part of the divine liturgy) was written on the Greek island of Patmos sometime in the second half of the first Common Era century, and details two visions experienced by the John of the title (whether or not he be apostolic) while on the island. The other key fact to remember about Patmos is the abundance of fly agaric mushrooms, especially around the mouth of the cave of revelation.