Summary: Who is the man of sin?
WHO IS THE MAN OF LAWLESSNESS?
There is a lot of difficulty in understanding this passage of Scripture. It is one of the most difficult. If not the most difficult in the entire Bible, it is at least one of the most difficult that Paul ever penned. No one (myself included) can be 100 % sure to have found who or what the man of lawlessness is.
There is just not enough information about. It is evident that we don’t have all the pieces of the puzzle. So, the best that can be done is to get the important things from it and move on. Like every other New Testament epistle, the Second Letter to the Thessalonians is an occasional letter (that means it was written with an occasion in mind) and was written to answer some problem that had risen.
Therefore, I will approach the text by setting forth the background of the Thessalonian Correspondence first, then by discussing who or what the man of lawlessness is.
“Concerning the coming of our Lord Jesus Christ and our being gathered to him, we ask you, brothers, not to become easily unsettled or alarmed by some prophecy, report or letter supposed to have come from us, saying that the day of the Lord has already come. 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. 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. Don’t you remember that when I was with you I used to tell you these things? And now you know what is holding him back, so that he may be revealed at the proper time. For the secret power of lawlessness is already at work; but the one who now holds it back will continue to do so till he is taken out of the way. And then the lawless one will be revealed, whom the Lord Jesus will overthrow with the breath of his mouth and destroy by the splendor of his coming. The coming of the lawless one will be in accordance with the work of Satan displayed in all kinds of counterfeit miracles, signs and wonders, and in every sort of evil that deceives those who are perishing. They perish because they refused to love the truth and so be saved. For this reason God sends them a powerful delusion so that they will believe the lie and so that all will be condemned who have not believed the truth but have delighted in wickedness.” (2 Thessalonians 2:1-12 (quickview) , NIV).
The Thessalonian church had its beginning during Paul’s second missionary tour. After Paul preached on Philippi of Macedonia for some time, he was thrown into prison there. Luke records in Acts 16:25 (quickview)  that while Paul and Silas were in prison "About midnight Paul and Silas were praying and singing hymns to God, and the other prisoners were listening to them." (Acts 16:25 (quickview) , NIV). They worship God, and their songs and courage becomes a means for the other prisoners to have a contact with the gospel. The Bible does not record neither the content of their prayers or that of their songs. But is does record that they were “singing hymns to God,” and soon after that God caused an earthquake that caused the prison to shake and them be set free. The city officials released Paul and Silas the next day, with their apologies, and they moved on to Thessalonica.