This quote of Jesus in regards to the end times is found in Matthew 24:34; Mark 13:30; and Luke 21:32. Jesus said, “Truly I say to you, this generation will not pass away until all these things take place.” The things that Jesus had been speaking of—the rise of the Antichrist, the desolation of the Holy Place, and the darkening of the sun—did not happen during the lifespan of people alive in Jesus’ day. Obviously, Jesus meant something different when He spoke of “this generation.”
The key to understanding what Jesus meant by “this generation will not pass away until all these things take place” is the context; that is, we must understand the verses that are surrounding Matthew 24:34, especially the verses prior to it. In Matthew 24:4–31, Jesus is clearly giving a prophecy; He is speaking of future events. Jesus had already told those living during His earthly ministry that the kingdom had been taken from them (Matthew 21:43). Therefore, it is imperative that Matthew 24–25 be seen as dealing with a future time. The generation that Jesus speaks of “not passing” until He returns is a future generation, namely, the people living when the predicted events occur. The word generation refers to the people alive in the future when the events of Matthew 24–25 take place.
Jesus’ point in His statement, “this generation will not pass away until all these things take place,” is that the events of the end times will happen quickly. Once the signs of the end begin to be observed, the end is well on the way—the second coming and the judgment will occur within that last generation. Jesus reinforced this meaning with a parable in Matthew 24:32–33: “Now learn this lesson from the fig tree: As soon as its twigs get tender and its leaves come out, you know that summer is near. Even so, when you see all these things, you know that it is near, right at the door.” A sure sign of summer is the leafing of the fig tree; a sure sign of the end of the world is that “all these things” (of Matthew 24) are taking place. Those who are on the earth then will have only a short time left.
Another interpretation is that Jesus’ prophecy in Matthew 24 has a “double fulfillment.” In this view, “this generation” is the people Jesus was speaking to at that moment—some of what He predicted was going to occur during their lifetimes. So, when the Romans destroyed Jerusalem in AD 70, Jesus’ prophecy was fulfilled in part; the fall of Jerusalem provided a foretaste of worse things to come. However, many aspects of Jesus’ prophecy did not occur in AD 70; for example, the celestial signs of Matthew 24:29–31. The main problem with the “dual-fulfillment” interpretation is that it does not harmonize with Jesus’ statement that “all” these things will take place in “this generation.” Therefore, it is better to understand “this generation” as referring to the generation alive when the end times events are actually occurring.
Essentially, Jesus is saying that, once the events of the end times begin, they will happen quickly. The age of grace has continued for a very long time. But when the time for judgment finally arrives, things will be wrapped up posthaste. This concept of God’s drawing things to a rapid close is echoed in many other passages of Scripture (Matthew 24:22; Mark 13:20; Revelation 3:11; 22:7, 12, 20).