Many believe that the temple has to be rebuilt in Jerusalem before the man of sin arrives on the scene.

I'm not so sure that Paul was speaking in this kind of language. For one thing Paul calls it a mystery. 

When Paul uses the word mystery he is referring to things that are hidden waiting for the appointed time of revealing.

So really I don't think one can say that the man of sin is waiting for the rebuilding of the temple, I believe that would be to simplify things to a systematic formula.

The man of sin opposes God and exalts himself against all that is genuinely sacred. 

He feigns religiosity, but his true character reveals that he is diabolic. 

His activity actually is according to the working of Satan. In some sense, the man of sin will sit in the temple of God. 

The temple, which Paul is alluding to, is not a reference to the Jewish house of worship. 

The Greek word is naos used by Paul eight times; never does he employ the term of the Jewish temple. 

In fact, after the death of Christ, the Jewish temple is never again called the temple of God. Rather it is used of the Christians body, or of the church as Gods spiritual house.

The suggestion is this: this unholy being is viewed as a Church character. 

A study of Paul's man of sin by Wayne Jackson.

What it sounds like Paul is saying, is that when this mystery is finally revealed the majority of people will not understand it.

This thing will look so much like the real thing, that any who oppose it will be considered as opposing God.

Let no one deceive you in any way: because unless there may first be an apostasy and the man of lawlessness may be revealed, the son of perdition,the one opposing and exalting himself above everything that is called God or divinity; so that he sits in the temple of God, showing himself off that he is God. Do you not remember that still being with you, I told you these things?And now you know that which hinders, that he should be revealed in his time. For already the mystery of lawlessness is working: only there is one now hindering, until he may be taken out of the midst; then indeed will the lawless one be revealed, whom the Lord Jesus will remove by the spirit of his mouth, and will exterminate by the brightness of his coming; whose coming is according to the energy of Satan in all power and signs and wonders of falsehood, and in all the deception of unrighteousness to those who perish; because they did not receive the divine love of the truth, that they might be saved. and on this account God sends to them the working of delusion, that they should believe a lie: in order that they may all be condemned who did not believe the truth, but took pleasure in unrighteousness.  2 Thessalonians 2, 3-12 

I'm not saying that the temple will not be rebuilt in Jerusalem, this still could happen, but I don't think that Paul was tacking this line of thought when he made these statements. 

This to me in real Pauline fashion, leads one to the deeper meaning than what he seems to say on the surface. 

I believe Paul was speaking in mystery, which was something not yet revealed.

Like the Mystery of Israel and the Church, this mystery waits for the appointed time, when mystery becomes visible event.


One should not get so dogmatic in a formulation of events, which must first come before the coming of Christ. 

The scriptures are very clear; no one knows the day and hour of his appearing.

These things that are coming to this world are sudden, like sudden destruction they take people by surprise.

But concerning the times and seasons, brethren, you have no need that I write to you; for you yourselves know well, that the day of the Lord is so coming like a thief in the night. When they may say, Peace and safety, then sudden destruction comes on them, as travail upon a woman in gestation; and they can not escape. But you, brethren, are not in darkness, that the day may overtake you like a thief: for you are all the sons of light, and the sons of day: we are not of night, nor of darkness; then therefore let us not sleep like the rest, but watch and be sober. 1 Thessalonians 5, 1-6 

Even though this mystery of lawlessness has been growing in their very midst, yet Once the thing is revealed, its usually to late, we miss it, We find ourselves fighting God, Like Israel of old, when the mystery of Christ was visibly revealed they missed him, but not only missed him, but also became willing participants in his death. 

If we have an ear to hear what the spirit is saying, then God has promised us that these things will not be a shock to us, when they are revealed. 
We will have knowledge before its made visible. 

These are very sobering deceptive days, If we are not in a state of communion before the Lord, then one will find himself drifting with every new wind of doctrine and spiritual manifestations, which are not coming, but are very present and alive now.

The bible says that the end of this age will be the most deceptive time in the history of the church; this makes me believe that these words are very relevant to the times in which we live.

This is the time of sifting; the only thing that will get us through is the reality of Christ as our life, he is the only sure foundation of our faith. Everything else that is not built on the foundation of Christ, and him crucified will be shaken.
 
For this reason we must pay much closer attention to what we have heard, lest we drift away from it. For if the word spoken through angels proved unalterable, and every transgression and disobedience received a just recompense, how shall we escape if we neglect so great a salvation! Hebrews 2-1,2,3