"Most people think John was writing at about the year 90 in the first century. That would be 60 years after the death of Jesus, and the eruption of Vesuvius happened in the year 79," she says. "Much of what we find in the Book of Revelation couched in the fantastic imagery are descriptions of events that for John were very close — the war in Jerusalem, the eruption of Mount Vesuvius, the Roman Emperors who were ruling at the time. ... It seems as though [John] reacted to that, saying, 'Jesus is coming and he is going to destroy all of this.' It was John's conviction that the destruction of Jerusalem was the beginning of the end of time that Jesus had predicted."
-- Elaine Pagels, 'Revelations: Visions, Prophecy, And Politics In The Book Of Revelation'