Do YOU know? there is a variety of opinions on who and what is restraining the mystery of iniquity, the working of Satan. the who and the what are connected.
Some of us do not think it is proper to say "the Holy Spirit will be taken out of the way" which is what you believe.
What is the mystery of iniquity and what restrains it? is it not the law? and the custodians of the law are angels and the chief of the angels is Michael. We see in the garden how God set the angel with the flaming sword to guard the tree of life lest man should stretch forth his hand and eat of it. The mystery of iniquity is man's striving for everlasting life ... without repentance.
The truth is, Paul TOLD US, but did it in a cloaked manner, perhaps so if his letter fell into Roman hands they would not understand. It seems he wrote it so only those who had his first letter would understand.
Did you notice how the earliest translations did verse 3?
1384 Wycliffe N.T.
That no man deceyue you in any maner / for no but
departynge aweye (or dissencon) schal come firste & the man of synne schall be schewid [shewed] the sone of perdicioune.
1534 Tyndale N.T.
Let no ma deceave you by eny meanes for the lorde commeth not excepte ther come
a departynge fyrst and that that synfnll man be opened ye sonne of perdicion
1535 Coverdale Bible
Let no man disceaue you by eny meanes. For the LORDE commeth not, excepte
the departynge come first, and that Man of Synne be opened, even the sonne of perdicion.
1539 Cranmer Great Bible
Let no man deceaue you by any meanes, for the Lorde shall not come excepte there come
a departinge fyrst, & that that synfull man be opened, the sonne of perdicion.
1549 Matthew's Bible
Let no man deceyue you by any meanes, for the Lord commeth not, except there come
a departyng first, and that, that sinful man be opened, the sonne of perdicyon
1565 Beza Bible
Let no man deceiue you by any meanes: for [that day shall not come,] except there come a departing first, and that man of sinne be disclosed, [euen] the son of perdition.
1575 Geneva Bible
Let no man deceiue you by any meanes for that day shal not come, except there come
a departing first, and that man of sinne be disclosed, euen the sonne of perdition.
Considering Paul's theme, the gathering (which will be departed from the earth as they are called up) which will be at His coming.
In short, the church is who is "taken out of the way" at this significant departing. It is the Holy Spirit, working through the church who is the restraining power. And it will be the power of the Holy Spirit that will empty the graves and catch us up.
Paul's argument is that this significant departing (the departing of the church) must come FIRST, then the man of sin will be revealed. And then, whoever sees these two events will have positive proof they are in the Day of the Lord - that it has already started.
Of course, some will say that it is the falling away (or the lack thereof before it happens) that is the restraining force. But if that were Paul's meaning, then where is his theme satisfied? (there can be no doubt the way Paul wrote this passage that the restraining force restraining, then taken out of the way has to be in that Greek word, Apostasia.