By refusing Jesus' kingdom invitation, Israel was keeping with its suicidal collision course with Rome. Jesus saw the coming conflagration and warned that unless Israel turned back there would be hell to pay within that generation. Jesus' message of judgment, the second coming of the Son of Man and the end of the age wasn't about some future heaven or hell. All of it--judgment, second coming and the end of the age--was happening within history, within the generation of those who listened, firsthand, to Jesus' warning.
This dire note of warning in Jesus' message picks up steam through the gospels and culminates in Jesus' final response during Passion Week. In the Olivet Discourse from the three synoptic gospels--Mark 13, Matthew 24 and Luke 21--Jesus brings his prophetic warnings to their full and final explication as Jesus' teachings regarding final judgment, the second coming and the end of the age are tied to the destruction of Jerusalem in 70 AD.
That Jesus was speaking about the destruction of Jerusalem is clear at the very start of the Olivet Discourse. Jesus had arrived in Jerusalem in the final days of his ministry. Jesus' disciples point out the beauty of the temple buildings and Jesus gives his prophecy about the destruction of Jerusalem and the temple:
Matthew 24.1-2So it is clear that the event being prophesied in the Olivet Discourse are the events of AD 70, the destruction of the temple.
Jesus left the temple and was walking away when his disciples came up to him to call his attention to its buildings. “Do you see all these things?” he asked. “Truly I tell you, not one stone here will be left on another; every one will be thrown down.”
Hearing this the disciples ask a question about the timing of Jesus' "second coming" and the "end of the age":
Matthew 24.3The association here is the one we've been tracking throughout the gospels. In the gospels the "second coming" and the "end of the age" occur during the destruction of Jerusalem in AD 70.
As Jesus was sitting on the Mount of Olives, the disciples came to him privately. “Tell us,” they said, “when will this happen, and what will be the sign of your coming and of the end of the age?”
If there is any doubt about that Jesus makes it clear later in the discourse:
Matthew 24.30-31The coming of the Son of Man will occur with the destruction of Jerusalem, the historical event the Olivet Discourse is predicting.
“Then will appear the sign of the Son of Man in heaven. And then all the peoples of the earth will mourn when they see the Son of Man coming on the clouds of heaven, with power and great glory. And he will send his angels with a loud trumpet call, and they will gather his elect from the four winds, from one end of the heavens to the other."
So if that's the second coming, what about the day of final judgment?
In the Olivet Discourse Jesus also connects final judgment to the events in 70 AD:
Luke 21.20-22In short, throughout the gospels when Jesus talks about judgment at the end of the age, about people being tossed into an "outer darkness" where there will be "weeping and gnashing of teeth," Jesus is talking about an imminent historical calamity. Jesus never describes "hell" as Christians tend to think about it.
“When you see Jerusalem being surrounded by armies, you will know that its desolation is near. Then let those who are in Judea flee to the mountains, let those in the city get out, and let those in the country not enter the city. For this is the time of punishment in fulfillment of all that has been written."
As the Olivet Discourse makes very plain, the destruction of Jerusalem--"When you see Jerusalem surrounded by enemies"--will be "the time of punishment in fulfillment of all that has been written."
The "time of punishment" spoken of by Jesus throughout the gospels isn't a "hell" at some far future Judgment Day. The "time of punishment" was an event in history, an event prophesied by Jesus before his death.
In sum, Jesus' eschatological imagination--all his talk about judgment, a second coming and the end of the age--was focused upon the concrete social, political and religious matrix of his time and place. Jesus' futurist prophesies were tied to imminent historical events, events he tied directly to the destruction of Jerusalem.
Here's how N.T. Wright sums it up in his book Simply Good News:
Jesus spoke of certain things that were to happen "within a generation." Many modern scholars have supposed that he was talking about "the end of the world," and that he was wrong. But, in those famous passages in the Gospels, Jesus is talking not about the end of the world but about the fall of Jerusalem...And of course Jerusalem did indeed fall to the Romans about forty years after the end of Jesus's public career...The end of the age, the second coming of the Son of Man, the final judgment where people are thown into the outer darkness where there is weeping and gnashing of teeth.
Jesus continually warned his fellow countrymen that if they didn't follow where he was leading, the result would be disaster. He used quite lurid language for these warnings. Even so, the message didn't really get through. He wasn't saying what they wanted him to say. But a lot of those warnings, taken out of context and interpreted through the lens of much later medieval beliefs, made it sound as though Jesus was warning people not that their city and nation would be destroyed but that they were going to hell. "Unless you repent," he says twice in the early paragraphs of Luke 13, "you will all be destroyed in the same way." Read that in the fifteenth century, and it's obvious what it means: unless you give up your sins, you will be thrown into hell for all eternity. Read it in the first century and a very different meaning should be equally obvious: unless you turn from your crazy path of nationalist rebellion against Rome, Rome will come and do to you what it has done to everyone who stands in its path. Jesus's contemporaries took no notice. The warnings came true.
According to Jesus, all these things have already happened.