In your previous post you said you believed it to be the body of Christ that would be the temple of God, and you quoted scripture to support that thought.
And I agree with that thought that the body of Christ is the temple of God.
But I'm not so sure that is the same temple of God mentioned in 2 Thess 2 that the image of beast is set up in to be worshipped.
It is possible that it isn't. But it is the only temple of God mentioned in the epistles that is not referring to the temple that still existed until 70 a.d. It never mentions that a third temple will be rebuilt. And certainly there is no need of one.
John 2:19-23
"Sir," the woman said, "I can see that you are a prophet. Our ancestors worshiped on this mountain, but you Jews claim that the place where we must worship is in Jerusalem."
"Woman," Jesus replied, "believe me, a time is coming when you will worship the Father neither on this mountain nor in Jerusalem. You Samaritans worship what you do not know; we worship what we do know, for salvation is from the Jews. Yet a time is coming and has now come when the true worshipers will worship the Father in the Spirit and in truth, for they are the kind of worshipers the Father seeks."
In order for 2 Thess to be read as a third physical temple being built, an entire eschatological presupposition must be applied to it. It may be a difficult passage to find God's meaning in, and I admit it is, but that does not warrant reading into it something that is antithetical to what is clear. Context helps, particularly the reason why Paul is addressing the issues he is and in the way he is. That can be found by searching search engines or books on the subject, and most convenient, chapter prefaces in a good study Bible that state the date and occasion of the writing.
So ....
Do you believe the temple of God mentioned in 2 Thess 2 (in which the beast is set up in to receive worship) is the temple that is the body of Christ?
Do you believe the RCC is included in the body of Christ?
As a people, individuals, I believe there are members of the body of Christ within the Catholic denomination. The religion itself with its teachings, is antithetical to Christ's church. It sets the boundaries of Christ's church rather that the first century apostles. It claims the same authority they have. It sets itself as the interpreter of Scripture rather than Scripture itself. It acknowledges the Trinity, the necessity of Christ's death and grace, but it claims to be the only dispenser of that grace. One can only get to Jesus through their traditions and priests. It has human mediators between God and man. It is idolatrous.
If the visible church, being representative of gathering as a community of God's people to worship and learn---as was the temple at Jerusalem for the Jews---then the man of lawlessness as a spirit of anti-Christ, has been in her midst even in the NT era, and ever since. It comes to deceive. It is Satan's war against the church. In these visible congregations we have both wheat and tares. This could be the meaning of the falling away, or apostasy. They would be the tares. It is deception that is being addressed by "anti-Christs". But no one can take anyone who is sealed by the Holy Spirit out of Christ.
It may be that Paul had in mind, without knowing that specifically, what would later become the RCC, which set itself up, and still does, as the one true Church of Christ. They backpedaled their language beginning in the 60's but they have never changed the tenets themselves. It certainly has spread to all the world and at times set out do kill and imprison all opposition. All that aside, if the "man of lawlessness" is an individual, setting himself in the temple of God (the church if that is what is meant) means just prior to Christ's return, imo would possibly mean a government leader who takes authority over all religion---a world religious leader--- who persecutes Christians and Christian institutions, not even allowing their existence.
However---- bottom line---what Paul does not say is when in history this will happen or how soon after it happens or to what extent or way, the apostasy will precede Christ's second coming. He merely says it will occur before his return. And he is specifically dealing with a teaching that had confused the church in Thess. that claimed Jesus had already returned. ANd the things he mentioned had not yet occurred which showed the teaching was false.