Jesus’ foretelling of the destruction of the temple was fulfilled in 70 A.D. when the Roman Legions besieged Jerusalem. His disciples, upon hearing His prediction, naturally wanted to know when such an unthinkable demolition would occur. Jesus, however, never revealed to them that He was speaking of a time forty years away.
According to Matthew’s account of Jesus’ Olivet Discourse, Jesus’ disciples not only asked about the future destruction of the temple, but also about the signs of His coming and the end of the age (Matt. 24:3). They may have assumed that the destruction of the temple, which He had just foretold, would occur at the end of the age. They may have been correct—if the rebuilt Jerusalem temple will also be destroyed. We read in Ezekiel 38:18-20 of a future earthquake in Israel that could certainly cause a rebuilt temple to be destroyed:
On that day there will surely be a great earthquake in the land of Israel….and all the men who are on the face of the earth will shake at My presence; the mountains also will be thrown down, the steep pathways will collapse and every wall will fall to the ground (Ezek. 38:20).
The prophet Zechariah also foretold of a day when the Lord will stand on the Mount of Olives, and when He does it will “split in its middle from east to west by a very large valley, so that half of the mountain will move toward the north and the other half toward the south” (Zech. 14:4).
In light of just those two prophecies, it would seem quite possible that the future Jerusalem temple could be demolished so that “one stone is not left standing upon another.”
Luke recorded a portion of Jesus’ Olivet Discourse that was not included by Matthew and Mark, and it seems to have specific application to the temple’s destruction that took place in 70 A.D. (Luke 21:20-24). For that and other reasons, some think that everything Jesus predicted in His Olivet Discourse was fulfilled by 70 A.D., even including His coming, which they interpret as His “coming in judgment” by means of Titus and the Roman Legions. Personally, I can’t accept that particular interpretation. Jesus spoke of cataclysmic events in the heavens, tribulation unlike any the world had seen before or after, false messiahs and prophets showing great signs and wonders, people seeing “the Son of Man coming in clouds with great power and glory,” and Him sending forth the angels to gather His elect “from the farthest end of the earth to the farthest end of heaven” (13:26-27). Those things did not occur around 70 A.D.!
Jesus’ frequent use of the personal pronoun you in His Olivet Discourse, as well as His promise, “Truly I say to you, this generation will not pass away until all these things take place” (13:30) are also presented as proof that everything Jesus predicted must have been fulfilled within forty years. But I would rather murder one scripture to save a hundred than murder a hundred scriptures to save one! Because all that Jesus foretold obviously did not come to pass within forty years of His Olivet Discourse, I can only conclude that He was not speaking of the generation that was alive then, but of the generation that would be alive when He returns. If that interpretation is correct, then we should expect that all that Jesus foretold will take place in the span of one generation, which I would peg at around seventy years.
In regard to the fact that Jesus frequently used the personal pronoun you as He foretold future events to Peter, James and John, and the claim that this proves Jesus’ words were fulfilled in their lifetimes, the fact is that neither Peter or James lived to see the destruction of Jerusalem in 70 A.D. James was martyred 12 to 14 years after Jesus’ Olivet Discourse (Acts 12:2). Peter was martyred between 64 and 68 A.D. Certainly none of them lived to see “the Son of Man coming in clouds with great power and glory,” or the angels gathering His elect from the four winds (13:26-27)!