1 Thessalonians 2: What to expect before Jesus returns?

The Thessalonians received a false letter of Paul saying that Jesus had already returned. They were facing troubles due to their faith, but if Jesus had already returned so, were everything in vain? were they abandoned by the Messiah? Paul wrote:

1-3 Now, friends, read these next words carefully. Slow down and don’t go jumping to conclusions regarding the day when our Master, Jesus Christ, will come back and we assemble to welcome him. Don’t let anyone shake you up or get you excited over some breathless report or rumored letter from me that the day of the Master’s arrival has come and gone. Don’t fall for any line like that.

Paul wrote that Jesus hadn't return and there will be signs before it happens:

- the apostasy 

- the man of Lawlessness - one man that sits in the temple of God (in Jerusalem?) proclaiming to be God.

Paul said that there is a Restrainer - one that is restraining the power of the Lawlessness.
Paul said:

13 But we should always give thanks to God for you, brothers and sisters beloved by the Lord, because God has chosen you from the beginning for salvation through sanctification by the Spirit and faith in the truth. 14 It was for this He called you through our gospel, that you may obtain the glory of our Lord Jesus Christ. 15 So then, brothers and sisters, stand firm and hold on to the traditions which you were taught, whether by word of mouth or by letter from us.

According to Paul, I (or a Thessalonian) was chosen for salvation through sanctification by the Spirit and faith in the Truth, so that I may obtain the glory of our Lord Jesus Christ. May the Spirit work on me; may I grow in the Truth; may I obtain the glory of Jesus (be resurrected).