It is you who needs to reread the scripture that you posted above.
Here is the same scripture again except I will highlight the most important part that you missed, which is "the Day of the Lord":
"Now concerning the coming of our Lord Jesus Christ and our being gathered together to Him, we ask you, brothers, not to be easily disconcerted or alarmed by any spirit or message or letter seeming to be from us, alleging that the Day of the Lord has already come. Let no one deceive you in any way, for [it] (the day of the Lord) will not come until the rebellion occurs and the man of lawlessness—the son of destruction—is revealed."
The 'coming of our Lord Jesus Christ and our being gathered together to Him, is not the same as "The Day of the Lord," which you failed to recognize.
The coming of our Lord and our being gathered to Him = the event of when the church is caught up to meet the Lord in the air.
The Day of the Lord = The time of God's wrath which follows the gathering of the church.
So it is "The Day of the Lord" that will not come until the apostasy occurs and the man of lawlessness is revealed. Both of those events are proof that "The Day of the Lord" has come and not our being gathered to Him, which takes place first.
All that you continue to do is misapply scripture. I have had this same discussion regarding this scripture many years prior to this. You're not presenting anything that I haven't already contended against.
The reason that Paul starts off with "Now concerning the coming of our Lord Jesus Christ and our being gathered together to Him" is because there were men in Thessalonica who were teaching that the Day of the Lord, the time of God's wrath, had already come. And since they knew Paul's teaching regarding the Lord appearing and our being gathered to Him to meet him in the air as taking place before God's wrath, they were concerned as to why they had not been caught up according to Paul's teaching.
Pay attention to the change that Paul makes in the scripture from 'our being gathered' vs. 'the Day of the Lord.'
I would suggest that you do a study on 'The Day of the Lord' scriptures. You will find that they all have to do with God's wrath being poured out upon the earth.
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I will completely sweep away
everything from the face of the earth,”
declares the LORD.
“I will sweep away man and beast;
I will sweep away the birds of the air,
and the fish of the sea,
and the idols with their wicked worshipers.
I will cut off mankind
from the face of the earth,”
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The great Day of the LORD is near—
near and coming quickly.
Listen, the Day of the LORD!
Then the cry of the mighty will be bitter.
That day will be a day of wrath,
a day of trouble and distress,
a day of destruction and desolation,
a day of darkness and gloom,
a day of clouds and blackness,
a day of horn blast and battle cry
against the fortified cities,
and against the high corner towers.
I will bring such distress on mankind
that they will walk like the blind,
because they have sinned against the LORD.
Their blood will be poured out like dust
and their flesh like dung.
Neither their silver nor their gold
will be able to deliver them
on the Day of the LORD’s wrath.
The whole earth will be consumed
by the fire of His jealousy.”
For indeed, He will make a sudden end
of all who dwell on the earth.
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The Lord's appearing and our being gathered to Him has nothing to do with the Day of the Lord, the time of God's wrath, except that it takes place prior to said wrath and that because we are not appointed to suffer God's wrath.