The two epistles of the Apostle Paul to the Thessalonians and were written between A.D. 51 and 53. Paul had taught them about the great tribulation that would usher in the Day of The Lord (Second Coming, Resurrection and Judgment).
It was due to the heavy local persecution they were tempted to think the Day of the Lord must have arrived. But Paul reminds them of all those things that were still yet to happen before the Day of the Lord could come. Ed. Stevens in his book, ‘The Decade Before the End’, writes; The revealing of the Man of Lawlessness had to occur before the Day of the Lord (the Parousia). Note that this epistle was written in AD 52-53, at least one year before Nero became Emperor (AD 54). His adopted father (Claudius) was still reigning. However, it seems more likely that the Man of Sin was fulfilled by Eleazar b. Ananias, the son of the same Ananias who arrested and tried Apostle Paul in AD 58. This may shed some light on Paul’s comments in 2 Thessalonians 2 that the Man of Lawlessness would