The man of sin... what are his revealed characteristics?
1. He is identified with the Son of Perdition (the phrase is used here, and as a title or designation of Judas, the apostate apostle of Christ who betrayed the Lord).
2. He opposes and exalts himself against God, and all that is called "god". Thus he acts as if he were the supreme being, in opposition to the true God as well as anything else that might be worshipped as deity.
3. He sits in the temple of God as though he was God, in God's place. God's throne is the mercy seat, thus the man of sin enthrones himself in a position on the mercy seat. Since that is in fact Christ's position as Mediator, King, and God, the man of sin replaces Christ and assumes Christ's preogatives as mediator, ruler, and God (source of redemption and salvation).
Now, according to Paul, the temple of God is the body of Christ, the church. In fact Paul in his epistles uses the word "naos" (temple) ONLY in reference to the church of God.
So the man of sin, whose arising coincides with, or at least following, the prophesied Apostasy (falling away), is a character IN THE CHURCH who usurps the place, position, prerogative, and purpose of God generally, and of Christ specifically. As God leads his people, the man of sin puts himself in that place, replacing the leading of the Spirit of God with his own leading.
As the Lord is the Mediator, the man of sin usurps that role and sets himself up as the go-between, between God and men.
As the Lord is the source and dispenser of grace, the man of sin makes himself the one who supplies grace, and apart from him grace cannot be dispensed.
As Judas, the original Son of Perdition, was an apostle, the man of sin arises from and assumes the guise of an apostle or minister of Christ. As Paul identified in
1 Cor 11, when we despise and abuse our brethren in the Supper we assume the role of Judas, and are guilty of the Body of our Lord as he was. Why? Because we abuse and betray the Body of Christ (the church), indicated by eating the bread that represents his Body in an unworthy manner. Therefore the man of sin likewise abuses the Body of Christ (the brethren).
Paul likewise warned the elders of the church at Ephesus that among the eldership would false leaders arise and would ravage the church (Acts
20:28-30). Verse 31 indicates this was a MAJOR concern of Paul's and that he ceased not for three years to warn folks of this coming apostasy and rise of Judas-elders in the church.
So it seems quite clear to me the man of sin is referring to the rise in the church of false leadership that would put itself (themselves) in God's place as the source of authority, direction, and grace (replacing the direction and leading of the Spirit with that of men who despise and ravage the flock. And like Judas, motivation is supplied in part by love of money. They are thieves with a pretense of piety.)
Historically, we find shortly after the death of Paul an apostasy in the church from apostolic truth. Trinitarianism, clericalism, catholicism, monasticism, the most aberrant doctrines imaginable begin to germinate. Along with this great falling away from truth there is the rise of the "monarchical episcopate", illustrated by Ignatius' writings where he taught that apart from the bishop (pastor) there is no church at all. Bishops replace the Spirit of God as leadership, as dispensers of grace, as mediators between God and men. They literally begin to put themselves in God's place, exalting themselves above God. This of course culminates in the Papacy, that bishop who literally claimed at one time to be "God upon earth".
Now, the bishop of Rome is not nowadays sitting in the temple of God (the RCC is not God's church). So it is error to suggest "the man of sin is the pope". But what does that leave? And what can possibly fit ALL the biblical data about this man of sin?
The answer is clericalism: the substitution of man-directed worship and man-centered leadership in place of GOD leading his church and dispensing grace to man. The priesthood of catholicism is but a symptom. The man of sin has enthroned himself IN EVERY CHURCH OF THE LORD that allows MAN to place himself in God's position, that allows humanism and human centered worship to rule, that allows men to be "the ones without whom you cannot be saved", that allows MAN to dictate that which only God in his Word and by his Spirit can properly dictate.