However, if the Temple fell, as Jesus apparently predicted it would, and if the message about Jesus and about His words included the insistence that Jesus was, in fact, the new Temple, that the Temple continued in those that believed in Him as Messiah (as the place in which the Creator God, by His Spirit, truly dwelled), that Israel’s God had raised Him from the dead, and that He was the Son of Man that had now gone before the Ancient of Days and received the power of the long-awaited kingdom of God, then a shift in loyalty and allegiance (faith) would be a very natural thing to occur.
If the Temple fell, and did so in line with Jesus’ predictions (perhaps one can think about the report of the abomination of desolation standing in the holy place and the author’s comment about the reader understanding), and if it was all tied-up with Jesus’ ministry, His crucifixion, His Resurrection, His ascension (understood to be the joining of the realm of the Creator God and the realm of man---the coming together of heaven and earth), the witness of the church, and the coming of the Son of Man to receive kingdom authority, then it would be more than clear that the Creator God had acted just as decisively within history as He had when the Temple had been destroyed by the Babylonians.
If the Temple had come to its end, and if the person that had predicted such a thing, who had been said to have been raised from the dead by the Creator God, was also reported to have insisted that He received His kingdom at the same time, then it would make all the sense in the world for the covenant people of the covenant God travel all the way down that path, worshiping Him and honoring Him as so deserved. Of course, historically, the actions of Gentile Christians did much to dissuade the Jews from traveling that path.
It would be one thing to go and preach a risen Lord. That would be a matter of meta-physical speculation and, when you get right down to it, faith. It would be quite another to go and preach a risen Lord, with a desire to accurately share the message that He preached, speaking about the Creator God’s kingdom coming through Him, with that tied to the fall of the Temple while the Temple of Jerusalem still stood. With a clear understanding that Jesus did, in fact, predict the fall of the Temple, then it may very well have been the most important issue at hand in the witness of the early church. The destruction of the Temple, with it occurring within the time frame that Jesus very clearly gave in one of His most straightforward answers, and as it appears that this is actually something that He must have said (otherwise it would not be so stringently reported and insisted upon by the Gospel authors), would be the thing that, rightly and understandably, gave weight to all other claims about Jesus.
Frankly, if He was truly going to be considered as a legitimate prophet, then the Temple had to come crashing down. It would be one thing to predict such a thing in a time of relative peace and stability under the Romans, and another thing altogether to insist upon such an occurrence when Jerusalem is surrounded by armies and the Jews are in the process of open rebellion against Rome. Here, one is forced to think about Jesus’ statement that many would come in His name (Messiah, Son of Man, etc…), claiming to be the messiah (Matthew 24:5) in the midst of wars and rumors of wars, and to consider his talk about people saying “Look, here is the Christ!” or “There He is!”, while adding that those that say such things during times of duress are not be believed (as it is only natural to make predictions about the possible destruction of the Temple when the Jews are in open revolt against Rome). So when Jesus says “For false messiahs and false prophets will appear and perform great signs and wonders to deceive, if possible, even the elect” (24:24), and then adds, “Remember, I have told you ahead of time” (24:25), better sense of this can be made.
Jesus spoke about the fall of the Temple “ahead of time.” Yes, Jesus made His prediction in association with the time of relative peace and stability. This was risky stuff for Jesus. There is great faith on display. If He was to be held up as anything but a failed messianic pretender, then it was ultimately necessary for the Temple to be destroyed. The Resurrection only mattered if Jesus received His kingdom as the Son of Man, and He had very clearly said that He would come to His reign (or His reign would be confirmed) when the Temple fell.