Birthed in Revival
We know from Scripture that the Messianic Community in Jerusalem was thriving in the first decades after the outpouring of the Holy Spirit in Jerusalem. When Paul comes back to Jerusalem to greet the apostles, they report to him:
On hearing it, they praised God; but they also said to him, “You see, brother, how many tens of thousands of believers there are among the Judeans, and they are all zealous for the Torah.” (Acts 21:20 CJB)
There are two interesting points worth noting. First, they are Torah-honoring Jewish believers. This does not mean that they necessarily followed all the traditions of Pharisaical Judaism, but that they suddenly found deep meaning in the commands and feasts that they previously only kept out of religious guilt or soulish zeal. This is reported to Paul as a good thing. There is no hint that they are moving away from Torah or their Jewishness, but closer.
Secondly, many translations use the English thousands for the Greek myriads. However a myriad is 10,000, so myriads plural, as is used in this verse, is correctly tens of thousands! We can safely conclude that Jerusalem and the surrounding areas had upwards of 30,000 or 40,000 believers and that, from a population of about 220,000! Acts 2 records 3,000 Jews coming to faith, and shortly thereafter, they numbered 5,000. 
But many who heard the message believed; so the number of men who believed grew to about five thousand. (Acts 4:4)
So 20 years later in Acts 21, 30,000 to 40,000 is not farfetched at all
Revival in Tel Aviv!
In addition to Jerusalem, God was moving mightily in other areas of Israel. Certainly in the Galilee, where Yeshua was raised, the Messianic movement was growing, but also in what is now the greater Tel Aviv area. There are two miracles recorded in Acts 9 at the hands of Simon Peter. First, in Lydda (Lod today, where Ben Gurion Airport sits) a crippled man is healed. From there he travels to Joppa and raises Tabitha from the dead. Those miracles resulted in a large number of Jews coming to faith.
All those [all Jews!] who lived in Lydda and Sharon (a large area covering the plains north of Tel Aviv) saw him and turned to the Lord. (Acts 9:35) [The miracle of Tabitha being raised from the dead] became known all over Joppa, and many people [all Jews!] believed in the Lord. (Acts 9:42)
I added [all Jews!] because at the time the Gospel was only being offered to Jews. It was in the next chapter, some time later, that Peter had the revelation that Gentiles could also find salvation in the Jewish Messiah.
In addition, many Cohenim (Temple Priests) came to faith.
So the word of God spread. The number of disciples in Jerusalem increased rapidly, and a large number of priests became obedient to the faith. (Acts 6:7)
James the Just—Yakov Hazadik
The congregation continued to grow under the leadership of Jacob (There were no first-century Jews named James) the brother of Yeshua. The historian Eusebius recounts Jacob’s martyrdom. At the time, he was held in high regard by virtually all sects of Judaism. So much so that he was called Jacob the Righteous. He prayed so much that he was nicknamed ‘camel-knees’ because of the callouses he developed.
However, the incredible growth of the Nazarene Movement (as they were called) led to deep feelings of jealousy. Josephus tells us that the governor of Judea had died. While the new one was on his way to Judea, the chief priest, Ananus, devised a plan to get rid of Jacob.
Josephus doesn’t reveal the plan in detail, but if we combine it with Eusebius, we get a clearer picture. The Pharisees requested that he come to the pinnacle of the Temple to address the Jews celebrating Passover. Interestingly enough, this is exactly where Satan took Yeshua to tempt Him (Matt. 4:5ff). Once there they challenged him to denounce Yeshua. He responded:
Why do you ask me about Yeshua, the Son of Man? He sits in heaven at the right hand of the great Power, and he will soon come on the clouds of heaven!
The Pharisees were furious, but the people shouted, “Hosanna to the Son of David!” The Pharisees then ascended to the pinnacle and threw him down. Jacob survived the fall and began to pray for them. “I beg of you, Lord God our Father, forgive them! They do not know what they are doing.” Like Stephen, they began to stone him, and finally:
A fuller (i.e., launderer) took out one of the clubs that he used to beat clothes and smashed James on the head, killing him with one blow. (source)
Josephus puts the death of Jacob at 62 CE while Eusebius says 69 CE. If it was 62 CE, it makes sense that Hebrews were written soon after, to encourage persecuted Jewish believers to not give up. Considering that Josephus was a contemporary of Jacob, I tend to agree with him.
Flee to the Mountains
Now, this is where things start to change drastically for the Jewish believers in Israel. Yeshua had told his disciples less than 40 years prior when they see the armies surrounding Jerusalem they should flee to the mountains.
But when you see Jerusalem surrounded by armies, then know that its desolation is at hand.Then let those who are in Judea flee to the mountains. Let those who are in the midst of her depart. Let those who are in the country not enter therein. (Luke 21:20-21)
“The Great Revolt” took place in 66 CE when the Jews rebelled against Roman rule. The Romans responded by leveling the city and destroying the Temple in 70 CE. As many as one million Jews died all over Israel.
However, the Messianic Jews, heeding the warning of Yeshua, fled. This is most likely a dual prophecy that will have a greater fulfillment before the coming of Yeshua. The believers in Jerusalem assumed, as many of us today, that they would see the return of Yeshua. Seeing that the prophetic warnings (Matt. 24 and Luke 21) came from Yeshua as he was teaching on the end times, they were sure that His return was near.
The historian Eusebius records that they were warned by an angel to flee.
For when the city was about to be captured and sacked by the Romans, all the disciples were warned beforehand by an angel to remove from the city, doomed as it was to utter destruction. On migrating from it they settled at Pella, the town already indicated, across the Jordan. (Weights and Measures, 15)
In Pella, they waited for the coming of Yeshua. When the war ended and Yeshua had not yet returned, the Messianic Jews returned to Jerusalem where they suffered persecution from the Jews who had fought the Romans—they were labeled as traitors. Josephus estimates that over one million Jews died in the war, nearly half of Israel's population. They were many other Jews who opposed the fighting, including Rabbi Yochanan ben Zakkai, who we will learn about in Part 2 next week. We can only guess that they fled in 68 CE, after the revolt, but before Jerusalem’s demise, and that they returned around 73 CE after the Zealots were defeated at Masada.
(Originally published October 18, 2014)
 A study was done based on Josephus’ numbers and that of other historians and scholars to conclude that the best guess for the population of Jerusalem and her surrounding cities was 220,000. (Josephus and Population Numbers in First Century Palestine, Anthony Byatt