The context is a prophesied event that must take place before the final events described in 2 Thes. 1. Namely -
2:3 Don’t let anyone deceive you in any way, for that day will not come until the rebellion occurs and the man of lawlessness is revealed, the man doomed to destruction. 4 He will oppose and will exalt himself over everything that is called God or is worshiped, so that he sets himself up in God’s temple, proclaiming himself to be God.
God's temple was still standing, despite the rending of the veil, & the Gospel of salvation through the Lord Jesus Christ. Jesus in his Olivet prophecy declared that it would be utterly destroyed before the generation that condemned him passed. That would be within 30-40 years & took place in AD 70. The Jewish leaders continued to reject Jesus & persecute those who believed the Gospel. They set themselves above their Messiah, God & Saviour, Jesus Christ.
Christians would however continue in Jerusalem until the signs Jesus gave in the Olivet prophecy would cause them to flee the doomed city. The Holy Spirit was maintaining his witnesses in the city until the time came to leave. The two witnesses - Moses & Elijah, the Law & the Prophets would stand as the final witnesses to their guilt.
Luke 16:31 “He said to him, ‘If they do not listen to Moses and the Prophets, they will not be convinced even if someone rises from the dead.’
Rev. 11 writes of those times - of the dreadful destruction.
There is no inspired record of the final years of Jerusalem when the prophesied chaotic events were taking place, but we have Roman records & Josephus.
We are now in a situation where believers are called to live faithfully through persecution & common tribulation until our Lord returns in glory for resurrection & judgment.
Mark 13:28 “Now learn this lesson from the fig tree: As soon as its twigs get tender and its leaves come out, you know that summer is near. 29 Even so, when you see these things happening, you know that it is near, right at the door. 30 Truly I tell you, this generation will certainly not pass away until all these things have happened.
31 Heaven and earth will pass away, but my words will never pass away.
32 “But about that day or hour no one knows, not even the angels in heaven, nor the Son, but only the Father. 33 Be on guard! Be alert! You do not know when that time will come.34 It’s like a man going away: He leaves his house and puts his servants in charge, each with their assigned task, and tells the one at the door to keep watch.
35 “Therefore keep watch because you do not know when the owner of the house will come back—whether in the evening, or at midnight, or when the rooster crows, or at dawn.36 If he comes suddenly, do not let him find you sleeping. 37 What I say to you, I say to everyone: ‘Watch!’ ”