The early believers of Thessalonica were troubled because of the prevalent false teaching that the day of the Lord was in process .... they thought they had missed the Lord's "harpazo" action to immortalize them:
Paul had discussed this issue with them earlier [
1Thessalonians 4, 5] and so he sets the record straight by explaining that the day of the Lord had not yet come ..... he also tells them why ..... because certain conditions were not present .... the coming of the lawless one and his following [the falling away].
The gathering Paul speaks of and the day of the Lord are not the same events and the Lord's immortalizing of the believer [both those asleep and those living at the time] will occur first ..... and then the day of the Lord will begin abruptly with no warning given to earth dwellers.
The day of the Lord will begin with His "hour" of trial [the coming tribulation period of 2,550 days] .... and will then include His coming millennial kingdom upon the earth for 1,000 years.
The term "last day" [the time frame of the day of the Lord] used in prophetic presentation is a period of time .... not just "one" 24 hour day .... and when this is used it is always presented as "at", or "in" the last day .... not "on" the last day.
Revelation confirms that the gathering noted in
2Thessalonians 2:1 is the Lord's call to immortalize the believer just before His coming hour of trial. Today's church is seen with Him dwelling heaven, in His temple, and around the throne just before, during, and at the closing of the tribulation period. [
Revelation 3:10; 4:4; 5:5-10; 7:9-17; 11:1; 12:12; 13:6; 17:14; 19:1-14; 20;4 (those on thrones)]