Referenced Scriptures:

Colossians 3:11

Hebrews 1:1-2

Genesis 12:1–3

Galatians 3:7–10

Galatians 4:22–33

Romans 4:9–12

Galatians 3:27–29

Matthew 3:7–10

Romans 2:28–29

Revelation 2:9

Revelation 3:9

On the destruction of Jerusalem in 70AD:
"Our city of all those which have been subjected to the Romans, was advanced to the highest felicity and was thrust down again to the extremist misery; for if the misfortunes of all men from the beginning of the world, were compared to those of the Jews, they would appear much inferior upon the comparison . . . to speak in brief, no other city every suffered such things, as no generation from the beginning of the world was ever more fruitful of wickedness."
As the plight of those within the walls grew worse, many attempted to escape, swallowing their money so that it would not be taken by the Romans. When this was discovered, any subsequent deserters were ripped open and disemboweled by the Romans in search of gold. Eventually most of the city and the Castle of Antonio had fallen to the invaders, and the Jews took refuge within the Temple precincts. They prepared to make a final stand there, still believing that God would intervene and save them. Finally the Holy Temple fell to the soldiers of the Roman Prince Titus; fire brands were used by the Roman soldiers to set the Sanctuary ablaze, and soon the magnificent temple ot Herod was a heap of smoking ruins. The Roman Legions now carried their standards, the Eagle and the Serpent into the Temple and sacrificed before them in the traditional Roman manner, an ox, a sheep and the ultimate abomination a pig. It has been estimated that at least one milion perished in the Siege of Jerusalem, and some ninety thousand survivors were sold into slavery, whilst seven hundred of the tallest most handsome captives were reserved for the March of Triumph through Rome by 'Titus and his Legions. Thus were fulfilled the predictions of the Lord Jesus, a generation earlier, and also of the prophet Daniel several hundred years before, when he had foretold concerning Titus and the armies of Imperial Rome.

- Josephus, The Jewish War

On the distancing of Christians from Jerusalem:

The people of the Church in Jerusalem were commanded by an oracle given by revelation before the war to those in the city who were worthy of it to depart and dwell in one of the cities of Perea which they called Pella. To it those who believed on Christ traveled from Jerusalem, so that when holy men had altogether deserted the royal capital of the Jews and the whole land of Judaea…"

— Eusebius, Church History

This heresy of the Nazoraeans exists in Beroea in the neighbourhood of Coele Syria and the Decapolis in the region of Pella and in Basanitis in the so-called Kokaba (Chochabe in Hebrew). From there it took its beginning after the exodus from Jerusalem when all the disciples went to live in Pella because Christ had told them to leave Jerusalem and to go away since it would undergo a siege. Because of this advice they lived in Perea after having moved to that place, as I said."

— Epiphanius, Panarion

For after all those who believed in Christ had generally come to live in Perea, in a city called Pella of the Decapolis of which it is written in the Gospel that it is situated in the neighbourhood of the region of Batanaea and Basanitis, Ebion's preaching originated here after they had moved to this place and had lived there."

— Epiphanius, Panarion

So Aquila, while he was in Jerusalem, also saw the disciples of the disciples of the apostles flourishing in the faith and working great signs, healings, and other miracles. For they were such as had come back from the city of Pella to Jerusalem and were living there and teaching. For when the city was about to be taken and destroyed by the Romans, it was revealed in advance to all the disciples by an angel of God that they should remove from the city, as it was going to be completely destroyed. They sojourned as emigrants in Pella, the city above mentioned in Transjordania. And this city is said to be of the Decapolis."

— Epiphanius, On Weights and Measures