Paul introduced his teaching by urging his readers not to be shaken from their adherence to the truth he had taught them by what they were hearing from others. The issue centered on Paul"s instructions concerning the Rapture ( 2 Thessalonians 2:1, cf. 1 Thessalonians 4:13-18). Other teachers were telling the Thessalonians that the day of the Lord had already begun ( 2 Thessalonians 2:2). This seemed to be a distinct possibility since Scripture describes that day as a time of tribulation as well as blessing. The Thessalonians were experiencing intense persecution for their faith. [source][source][source]
"False starts have been a common phenomenon among movements predicting the imminent end of the age as people"s expectations exceed their patience." [1][source]
Many people throughout church history have confused the teaching of the apostles that Christ could come at any moment (for believers at the Rapture) and the unbiblical idea that He would come at any moment. The first correct view is the doctrine of imminence, but the second incorrect view involves date setting. [source][source][source]
The false message seems to have gained a hearing also because it came from several different sources. Paul referred to alleged prophetic Revelation , the teaching of other recognized authorities, and a letter Paul had supposedly written that had arrived in Thessalonica (cf. 2 Thessalonians 3:17). If the day of the Lord had begun, how could Paul say the Lord"s return for his own would precede that day ( 1 Thessalonians 1:10; 1 Thessalonians 5:9)? Note that Paul had taught them a pretribulation Rapture. [2][source]
"The supposed doctrinal difficulty lies in the failure to distinguish between parousia [3] and the day of the Lord. The advocates of the false teaching at Thessalonica conceived that the day of the Lord was not merely "at hand," which was true ( Romans 13:12), but actually "present," which Paul denied. Such a view denied the believer the hope of the imminent rapture." [4][source]
The subject of 2 Thessalonians 2:1-12 is "the day of the Lord" ( 2 Thessalonians 2:2). This day, as the Old Testament and the New Testament refer to it, includes the Tribulation, the Second Coming, the Millennium, and the great white throne judgment (cf. Psalm 2:9; Isaiah 11:1-12; Isaiah 13; Joel 2; Amos 5:18; Zephaniah 3:14-20; et al.). [2][source]
Some premillenarians include the Rapture in the day of the Lord. [6] But others exclude it. [7] Those who include it point to the Rapture as the beginning of God"s direct intervention in human history again. They also stress that the parousia ("coming" or "appearing") refers in Scripture to the Lord"s coming and to events that follow the Lord"s coming. Those who exclude it do so for two reasons. The Rapture is a church event whereas the day of the Lord is an Israel event, and the beginning of that day resumes the chronology of Daniel"s seventy weeks. The seventieth week begins when the Antichrist signs a covenant with Israel allowing the Jews to return to their land ( Daniel 9:27). I favor the second view. While the term parousia is broad and refers to the Rapture and to many events that follow it, the term "the day of the Lord" seems more narrowly defined in Scripture and nowhere specifically includes the Rapture. [source][source][source]
"This great contrast of attitudes toward the beginning judgment phase of the Day of the Lord and the Rapture [8] is another indicator that the Rapture is not the beginning or any part of the Day of the Lord. Rather, it will be a separate event. Therefore, Paul"s reference to the Day of the Lord in 2 Thessalonians 2:2 is not a reference to the Rapture." [2][source]