However, I think you have to twist a whole lot of scriptures if you would like to push all end-time prophecies on the destruction of Jerusalem, claim that the new covenant did not fully start until 70 AD and that the destruction of Jerusalem was "the end of the age" - meaning the end of the Old Testament age/time period....
Building theology on external sources
When it comes to forming my theology on essential doctrines, I have always been a firm believer in using the Bible only. Therefore, I have some problems with the view of the destruction of Jerusalem being the end of the old covenant.
This does not mean that we can't learn from history and the writings of the church fathers, but that should be additional knowledge.
For instance, I might learn from studying history that they did not start to baptize infants before a few hundred years after the book of Acts. Even though this knowledge can strengthen my view on baptism, this should be only additional knowledge that confirms my view and not the basis for my theology on baptism. I should be able to come to a strong conclusion on baptism without this knowledge.
The issue of when the old covenant ended and the new one was fully implemented is quite important because it touched a very fundamental part of our faith - our covenant with God. End-time prophecies also fill quite much space in our Bible and are therefore a big element of our faith. So, what I need to know to form my theology on these issues should come from the Bible and not be based on external sources.
One of my problems with the destruction of Jerusalem being the fulfillment of God’s wrath, the final end of the old covenant and the time when the new covenant was fully established is that in order to come to this conclusion I basically need to have read history, because this happened in the year 70 AD and is not mentioned in any of the New Testament writings.
Yes, there might be verses from the epistles to the Hebrews I can link to this, but I can only do that if I first have read history and know that Jerusalem was destroyed in the year 70 AD.
I believe that the Bible is for common people and that all I need to know for a strong, healthy and vibrant walk with God can be found in the Bible alone. Other books can add to that knowledge, but they should only confirm what the Scriptures are already saying.
When Jesus cried out "It is finished", I believe it was so. I know that the disciples had not been baptized in the Holy Spirit yet, because that did not happen before Acts chapter two. However, with His own blood Jesus had signed the new agreement between God and Man, as well as made provision for people to be born again, filled with the Spirit and enter into a new covenant with God.
Didn't the first Christians live fully under the new covenant?
It makes no sense to me that the first apostles and disciples were not walking in the fullness of the new covenant, since most of them were either dead or inactive after the year 70 AD. When I read the book of Acts, it seems to me that they had a better grasp of the new covenant than we have today.
Matthew 24:14 says:
And this gospel of the kingdom will be preached in all the world as a witness to all the nations, and then the end will come.
— Matthew 24:14
Jesus said the disciples would receive power when the Holy Spirit came upon them and not when Jerusalem was destroyed.
Of course, God is bigger than what we read in the Bible, because no book would be able to contain Him. Even Paul the Apostle did not claim to "have it all" (Philippians 3:12-15). That does not mean that the new covenant is not complete, though - because then it would still be incomplete.
How could believers know?
If what happened in the year 70 AD was the complete end of the old covenant, and the signs Jesus gave should help them to know that this was the end, how would these signs help believers in other parts of the world known then?
There was no TV, radio or Internet at that time and the post system was not exactly "express delivery". Therefore, if these signs should help believers know when the end of the age (as meaning the old covenant time period) was completely finished, then the only believers it would have helped would have been the ones living in Jerusalem. It would have taken a long time before the history of the destruction of Jerusalem and the event that surrounded it would have been written down for others to read.
Thus, if the specific sign Jesus gave should have helped people understand that the end had come, then most Christians living at that time had no gain of what Jesus said because they had no possibility of knowing that these signs were taking place. The end came and went and most Christians were ignorant about it - in fact most Christians still do not know about it.
If this only had to do with the Bible prophesying about a future historic event I would have no problem with it. The Bible is full of prophecies of future events, some that have happened and some that have not happened yet. Some of them I know about, many I don't know about and when it comes to my covenant with God it doesn't really matter.
However, when you tie our covenant with God with a historical event that is not mentioned in the Bible, and the signs that were given to help us know when the time came were impossible for most Christians (at the time it happened) to know, then I think it becomes problematic.
I believe that what I need to know, when it comes to my new covenant with God, can be found within the pages of the Bible. Then I can give the Bible to a new believer in a remote area of China and say: "Here you can read everything you need to know about God, eternal life, your new relationship with Him, and so on."
3 different events
I also think it is important to notice that the disciples were actually asking three different questions. Some miss this and say that they are asking only two. The first one is "when the temple will be destroyed", the second one is "what will be the sign of Your coming" and the third one, embedded in the last sentence, is "and what is the sign of the end of the age".
“Now as He sat on the Mount of Olives, the disciples came to Him privately, saying, "Tell us, when will these things be? And what will be the sign of Your coming, and of the end of the age?"
— Matthew 24:3
For instance, he mentioned that there would be false Christs or people claiming to be Christ twice. First in Matthew 24:5, when he is answering their first question and then He mentions it again in Matthew 24:23 in His answer to their second question.
Why does he mention this two times, not as a repetition, but as two different instances? This is because this would occur both before the destruction of the temple and as we get close to the return of Christ.
When it comes to the destruction of the temple and the end of this age, He gives us specific signs to look for, and He tells us:
"Now learn this parable from the fig tree: When its branch has already become tender and puts forth leaves, you know that summer is near. So you also, when you see all these things, know that it is near—at the doors!”
— Matthew 24:32-33
"But of that day and hour no one knows, not even the angels of heaven, but My Father only. But as the days of Noah were, so also will the coming of the Son of Man be.”
— Mat 24:36-37
God does not exaggerate
Another point to notice is that when it comes to the question of what the sign of the end of the age is, Jesus is stating:
“For then there will be great tribulation, such as has not been since the beginning of the world until this time, no, nor ever shall be. And unless those days were shortened, no flesh would be saved; but for the elect's sake those days will be shortened.”
— Matthew 24:21-22