I appreciate and concur with much in your responses. Here is some historical commentary and context from two apologists of the early Church:
The early church believed that the imperial Roman empire, under which the church was then living, was the restrainer which would eventually be "taken out of the way", but which was forestalling the emergence of the papal Roman empire, which Paul describes as the lawless one; and its eventual apostasy. Notice in the related verses in 2 Thess. 2 that Paul does not reveal the identity of the restrainer. If Paul had believed that the Holy Spirit or the Church was the restrainer, there would have been no reason for him not to explicitly name either one. But Paul did have a reason.
John Chrysostom (347-407 AD), an apologist of the later early post-apostolic era, reveals it:
"Because if he meant to say the
Spirit, he would not have spoken obscurely, but plainly, that even now the
grace of the
Spirit, that is the gifts, withhold him...But because
he said this of the Roman empire, he naturally glanced at it, and speaks covertly and darkly. For he did not wish to bring upon himself superfluous enmities, and useless dangers. For if he had said that after a little while the Roman empire would be dissolved, they would immediately have even overwhelmed him, as a pestilent person, and all the faithful, as living and warring to this end."
Paul did not wish to jeopardize the Church by attracting the attention of the Roman authorities.
History subsequently confirmed the validity of Paul's inspired prescience.
Chrysostom was affirming what
Tertullian (160-220AD) had said over a century earlier:
ON THE RESURRECTION, CHAP. XXIV
"For the mystery of iniquity doth already work; only he who now hinders must hinder, until he be taken out of the way."
What obstacle is there but the Roman state, the falling away of which, by being scattered into ten kingdoms, shall introduce Antichrist upon (its own ruins)? "And then shall be revealed the wicked one, whom the Lord shall consume with the spirit of His mouth, and shall destroy with the brightness of His coming: even him whose coming is after the working of Satan, with all power, and signs, and lying wonders, and with all deceivableness of unrighteousness in them that perish."
Re. your comment:
"Certainly we see no evidence of it in the first 1500 years of Christ's Church, and the notion that Christ had no disciples back then, save the Apostles themselves, does a grave injustice to the work of the Holy Spirit; who quickens us in every generation to Christ."
There has always been, and will always be, the true Church. But the evidences of apostasy in the institutionalized church began in the 6th century, and reached their zenith in the 16th century. God raised up the Reformers to reclaim His True Church from the spiritual bondage which had enslaved it.