Do not quickly get worried and alarmed by any message that the Day of the Lord has already come.
2 Thessalonians 2:1-3a
Now I want to write to you about the time when our Lord Jesus Christ will return and when God will gather us together to where Jesus is. My fellow believers, I urge you that you think calmly about any message that claims/says that the Lord has already come again. Do not be shaken or alarmed/worried by any such message. It does not matter if it is a message that someone claims God's Spirit revealed to him, or if it is some other message that someone has spoken, or whether it is a message that someone claims that I wrote in a letter. Do not allow anyone to deceive you in any way with the result that you believe any such message.
The Lord will come only after that time when the man who will sin very greatly will appear.
2 Thessalonians 2:3b-5
The Lord will not come [MTY] immediately. First, many people [PRS] will rebel against God. The result of their rebelling will be that they will accept and obey the man who will sin very greatly against God. He will be the supreme enemy of God. He will proudly exalt himself above everything that people consider to be some god and above everything that people worship. As a result of wanting people to worship him, he will even enter God's Temple and sit down there to rule. He will publicly proclaim that he himself is God! But God will certainly punish that man forever! ◄I am sure that you remember that I kept telling you these things while I was still with you there in Thessalonica./Do you not remember that I continued telling you these things while I was still with you there in Thessalonica?► [RHQ]
This man will be revealed by God when he who is now preventing him from being revealed will have been removed by God.
2 Thessalonians 2:6-8
You also know that there is something (OR, someone) that is preventing this man from being revealed { from revealing himself}. This man is being ◄held back/restrained► now for him to be revealed {that he reveal himself} at the time that God has planned [MTY]. Although Satan is already secretly causing people to reject God's laws, ◄the one/God► who is preventing this man from revealing himself now will continue to prevent him from doing that until he/ God removes him. It is then that God will allow this man, who rejects God's laws completely, to be revealed {to reveal himself}. Then the Lord Jesus will destroy him, by simply commanding it [MTY]. Jesus, by his own glorious arrival, will cause him to become completely powerless.
When this man is present, he will completely deceive those who will perish.
2 Thessalonians 2:9-12
But before Jesus destroys him, Satan will make him very powerful. As a result, he will do all kinds of supernatural miracles and amazing things [DOU] that will seem as though God has enabled him to do them. 10 And by doing wicked things, he will completely deceive those who will certainly ◄perish/go to hell►. He will deceive them because they will have refused to love the true message. So they will not be saved {God will not save them}. 11 So, God, by his power, will enable this man to easily deceive people, so that they will believe what this man falsely claims/says that he is. 12 The result will be that everyone will be rightly condemned {that God will justly condemn everyone} to be punished who did not believe the true message, but who instead gladly chose to be doing what is wicked.
God chose you in order that you should be saved and share in Christ's glory.
2 Thessalonians 2:13-14
13  Our fellow believers, whom our Lord Jesus loves, we thank God very frequently for you. It is appropriate/right for us to do that, because God chose you ◄from the beginning [MTY] of creation/before the world existed► in order that he might save you as a result of your believing the true message and as a result of God's Spirit setting you apart for God. 14  We thank God that he chose you as a result of our proclaiming the message about Christ to you, in order that you might ◄share in/have► some of the glory that our Lord Jesus Christ has.
Continue believing the teaching that we gave to you.
2 Thessalonians 2:15
15 So, our fellow believers, continue to be firm concerning what you believe; that is, continue believing the true teaching that we gave to you by our speaking to you and by our writing a letter to you.
We pray that our Lord Jesus Christ himself will encourage you and cause you to continue doing and speaking what is good.
2 Thessalonians 2:16-17
16 Our Lord Jesus Christ himself and God, our Father, loves us and encourages us and causes us to confidently expect to receive the eternal things that he has promised to give to us as a result of Christ acting kindly toward us in a way we did not deserve. 17  We strongly pray that God and Jesus together will encourage you! And we pray that they will cause you to continue doing and saying things that God considers to be good.