Tom Butler said:
Several of the early church fathers believed it was the Roman empire, which still existed at that time. Several later theologians held that the restrainer was human government
Actaully Tom, it would be better to get a little more specific here.
It was not till the 3rd century that this view came into being espoused by Turtullian and Chrysostom. However this is 150 years later.
Several felt it was the Church (and the HS), and when the church was raptured, so did the restraint.
These would include the vast majority of 1st, 2nd, and including much of the 3rd century early church fathers.
One view is that the restrainer is the revived Roman empire of the future.
And a few held that it is the archangel Michael. They cite several reasons:
1. The Holy Spirit never did exercise any restraining in any verse in the Bible where he is mentioned.
2. Daniel 12:1 "And at that time shall Michael stand up, the great prince which standeth for the children of thy peace; and there shall be a time of trouble, such as never was since there was a nation even to that same time....." The tribulation starts when Michael stands up.
3. Revelation 12:7-9 "And there was war in heaven: Michael and his angels fought against the dragon; and the dragon fought and his angels, and prevailed not, neither was their place found any more in heaven. And the great dragon was cast out, that old serepent, called the Devil and Satan, which deceiveth the whole world; he was cast out into the earth and his angels were cast out with him." When the Devil is kicked out of heaven, he unleashes his representative and the tribulation begins.
Is it Michael? Gee, I don't know. [/quote]
As I stated previously, it can't be.
1. (in relation to the above #1) The Holy Spirit IS said to restrain but the word is to reprove in John 16:7-8. To reprovemeans not only show them but also implies a correcting of them regarding sin. Thus sin can not go unchecked.
...1b.Michael is never said to be a restrainer but a angel who guards or protects the Jewish people. THIS is Key. The one who will let (or restrains) is speaking speficially in relation no to a people but lawlessness (or sin) of the world and particular the one who will bring it into being. Is Michael ever said to be doing this or even insinuated to be so powerful that he like God Himself? Remember when Michael was said to be contending (arguing) over the body of Moses. How did he defeat Satan? He said - The Lord rebuke you. He has no power to overcome much less the power to continue to restrain Satan - Only God does.
2. If you will read Chapter 11 of Daniel you will find that Michael does not stand up till the latter most part of the Tribulation Now watch this

The context of Dan 12:1 IS NOT that Michael stands and the tribulation occurs but that Michaels standing DURING the Tribulation (as a protector just as in Dan 10)and the Nation shall be delivered/saved, everyone who is found in the Book. Paul says the same thing in Rom 11.
Dan 12:1 And at that time shall Michael stand up, the great prince which standeth for the children of thy people: and there shall be a time of trouble, such as never was since there was a nation [even] to that same time: and at that time thy people shall be delivered, every one that shall be found written in the book.
And Paul in Romans 11:
Rom 11:1 I say then, Hath God cast away his people? God forbid. For I also am an Israelite, of the seed of Abraham, [of] the tribe of Benjamin.
Rom 11:4 But what saith the answer of God unto him? I have reserved to myself seven thousand men, who have not bowed the knee to [the image of] Baal.
Rom 11:5 Even so then at this present time also there is a remnant according to the election of grace.
Rom 11:15 For if the casting away of them [be] the reconciling of the world, what [shall] the receiving [of them be], but life from the dead?
Rom 11:25 For I would not, brethren, that ye should be ignorant of this mystery, lest ye should be wise in your own conceits; that blindness in part is happened to Israel, until the fulness of the Gentiles be come in.
Rom 11:26 And so all Israel shall be saved: as it is written, There shall come out of Sion the Deliverer, and shall turn away ungodliness from Jacob:
Rom 11:27 For this [is] my covenant unto them, when I shall take away their sins.
Rom 11:28 As concerning the gospel, [they are] enemies for your sakes: but as touching the election, [they are] beloved for the fathers' sakes.
Thus his standing up is when is in defending them till their savior comes and actually delivers them - all who are written in book. Thus though an entire Nation is saved, not everyone in the Nation is saved.
3. That portion of scripture can not be used to validate their view because it is a "flash-back" to what has 'already' transpired. If you continue reading you find that AFTER Satan is cast out he persecutes Israel who gives birth to a 'man child' (Jesus) . But this is true up till verse 15 (because Israel as a Nation was removed from Satan persecutions 'hidden' for a great while). Then she (the Nation Israel) re-emerges in verse 15 where Satan again turns to attaking/persecuting her. However the earth opens up and swallows whatever this 'flood' is so that Satan is even angrier than before. So he turns his attention to those 'true believers' who are what the passage calls "the remnant of her seed" ,those who keep the commandment of God AND have the testimony of Jesus Christ (saved).
Thus it is impossible for the 'restrainer' to be Michael.
I do find it interesting that in II Thess 2:6, Paul said he had already revealed the identity to the Thessalonians and was just reminding them of a few things he had told them before. Only, he didn't say "who withholds," he said "what witholds." Hmm.
Umm.. Hold on.
He does not only state 'that' but also 'He", let us not forget that.
But this also is exactly what I was saying. The Holy Spirit is 'the Restrainer' (he) and his means is the Church (that). In order for this 'holding back' to be allowed to be loosed that which restrains (in the general sense) must be removed and thus so to must the Holy Spirit in this sense (The Restrainer) be removed.
A
good article can be found here which speaks about the early church fathers views and looks biblically at the foreground which conceptualizes whom the scriptures speak of the 'restrainer' as.