Perhaps the most important of those reasons is that Jesus himself warns against it in this very passage. The disciples ask Jesus when all these things will happen to which he replies:
"See that you are not led astray. For many will come in my name, saying, 'I am he!' and, 'The time is at hand!' Do no go after them." (v. 6)This, combined with Jesus' admonition in Acts 1 that no one knows the time and date of Jesus' return, should be enough to put to rest every attempt by Christians to put together any kind of "End of the World" timetable or blueprint.
A second important facet of Jesus' discourse in this passage is that it is all ultimately a response to comments about the temple. The chapter opens with the story of a poor widow putting two copper coins into the temple offering and Jesus commenting that she has given more than all the rest because she has given all she had. Afterward, some of those present are marveling at the temple in all its glory. The Jerusalem temple was indeed a building that would have inspired awe by ancient standards. It was both enormous in its construction and ornate in its craftsmanship. But rather than joining in their gawking over the temple, Jesus says:
"As for these things that you see, the days will come when there will not be left here one stone upon another that will not be thrown down."This prophecy by Jesus was quite literally fulfilled in 70 A.D. when the Romans put down a Jewish insurrection and burned the temple to the ground in the process. Far from being a prediction about the future, much of what Jesus speaks about here takes place in the disciples' own lifetime. In fact, Luke makes a point of speaking about the disciples in Acts in a way that fulfills Jesus' words here. In v. 12-14 Jesus says:
"But before all this they will lay their hands on you and persecute you, delivering you up to the synagogues and prisons, and you will be brought before kings and governors for my name's sake. This will be your opportunity to bear witness. Settle it therefore in your minds not to meditate beforehand how to answer, for I will give you a mouth and wisdom, which none of your adversaries will be able to withstand or contradict."In Acts 4, Luke tells the story of Peter and John being arrested and brought before the religious leaders because they have been preaching in the name of Jesus. When they are given the chance to defend themselves, Peter is filled with the Holy Spirit and speaks eloquently about Jesus. When the religious leaders heard Peter's speech they are astonished that some with education could speak as Peter has just done. Furthermore, seeing the formerly crippled man that Peter had just healed standing next to them, the council is unable to speak in opposition to what Peter has just said. Jesus' words in Luke 21 are fulfilled in Peter.
Thirdly, it is important to recognize the kind of literature we are dealing with in this passage. Like its similar sounding counterparts in Daniel and Revelation, this passage is an example of apocalyptic literature. The Greek word from which this literature derives its name means to reveal or uncover. The purpose of apocalyptic literature is to pull back the curtain of everyday, visible reality and expose the greater reality that easily remains unseen. So in Revelation, for example, John portrays seemingly harmless compromise with the Roman Empire as nothing short of keeping company with a Great Harlot who derives her seductive power from the unholy psuedo-trinity of false prophet, satanic beast, and devouring dragon. Likewise, Jesus is uncovering an important reality for his disciples when in v.27 he describes himself as the Son of Man described in Daniel 7. A few verses from that chapter of Daniel will suffice to show why that would be a reassuring image for those who count themselves followers of Jesus.
"I saw in the night visions, and behold, with the clouds of heaven there came one like a son of man, and he came to the Ancient of Days and was presented before him. And to him was given dominion and glory and a kingdom, that all peoples, nations, and languages should serve him; his dominion is an everlasting dominion, which shall not pass away; and his kingdom one that shall not be destroyed." Daniel 7:13-14In other words, in the midst of all this tragedy, when things seem most hopeless, Jesus' disciples are still to raise their heads and their hopes high because their redemption is near. Even as nation rises up against nation, Jesus is the one to whom dominion over all the nations has been given. Whatever chaos the powers that be may cause, Jesus is the one true power who reigns supreme.
In some ways, this may seem an odd message for this time of year. We would rather think of holiday cheer and a cute baby boy born in a manger. But the gospels will not let us forget that the baby boy in the manger is the one who rules the nations. Furthermore, this is an appropriate word for the first Sunday of Advent for it is the coming of Christ and his kingdom which is our hope. As Christians, there is a certain sense in which we are always living in a season of advent because it is Christ's cosmic reign of peace and justice which we eagerly anticipate even as we live in a world of wars and rumors of wars. We are always a people who are waiting, a people leaning into the future, living into the day when the Son of Man will come in the clouds with power and great glory. May His kingdom come.