How can the Papacy be the Antichrist if Rome does not deny “that Jesus is the Christ” nor deny “the Father and the Son” (1 John 2:22)?
Reformed Scholastic theologian Francis Turretin answers this objection in his treatise Whether It Can Be Proven the Pope of Rome is the Antichrist, sections 17 and 49.
“Although it is certainly understood that apostasy is a significant and notable characteristic of Antichrist, we must not conclude that every soft of defection from the faith, including a public denial of Christianity (which other religions are known for), is meant here [by “falling away” in 2 Thess. 2:3]. Nor is the force of our original argument lost because of the lack of an apparent defection from the faith on the part of the Papacy.
“The Pontiffs desire they be eliminated [as suspects who perfectly fit the description of the Antichrist] because they do not specifically deny Christ [1 John 2:22]. However, any extraordinary defection from the faith certainly suffices for one to be considered apostate, although one does not totally deny the faith. In this way, the word αποστασιας; corresponds to the Hebrew תִּמְרְדוּ, meaning to rebel, in which sense the Reubenites and Gadites, because of an altar erected near the Jordan River, are said to have apostatized or to have rebelled against the Lord (Joshua 22:18-19). It was not, mind you, that the children of Israel believed these tribes to have completely thrown off religion, but because they were performing religious rites in a place [and of a type] other than that established by God, the Israelites separated themselves from those brethren who were rebellious to the mandate of the Lord.
“Thus, even if Christianity is not absolutely denied, defection from the faith is still considered very real if the errors in question are of capital import, especially if the idolatrous cults are introduced against it. To be sure, idolatry in Scripture is so often designated as apostasy and defection. In which case we are to understand that the apostasy of the Antichrist is not that of complete abnegation of Christianity, but, on the contrary, he is said to make his seat in the temple of God [2 Thess. 2:4], that is, in the Christian Church, in order to exercise his tyranny. And it is in the name of Christianity that he will darken, introducing his cursed apostasy.” (Section 17).
. . .
“We now address our opponents’ fourth response against the truth of the papal Antichrist. In contention is the interpretation of Scripture which predicts Antichrist’s assault and denial of Christ [1 John 2:22]. Is it to be understood as open and explicit as far as external profession, or implicit and hidden as far as the actual truth of the matter?
“We Reformed hold firmly that the Antichrist must deny Christ, not in the first, but in the second manner; that he must be a disguised enemy of Christ, who, under the pretense of the name of Christ would rule over the Church of Christ, attacking the person of Christ, his offices and his good works. It must not, therefore, be expected that the Antichrist would openly profess himself the enemy of Christ, (although in reality he shows himself to be such), nor would he boast himself to actually be the Christ, which the pseudo-christs did. Instead, he would appropriate for himself the very things which are Christ’s alone, which we have shown the Popes have actually done, by citing numerous proofs.
“Augustine’s observation on this point is well taken, “Let us not be attentive to the tongue, but to the facts. Similarly, Antichrist is a liar, who by his mouth professes Jesus Christ, yet by his deeds denies him.” Thus, when the Pope usurps the triple office of Christ, he destroys Christ’s gospel by his own traditions, also destroying Christ’s redemption by his own indulgences, purgatory, masses, and rewards; all this while verbally professing Jesus to be the Christ. Notwithstanding his profession, he must be regarded as having denied Christ, together with the Father, by his very deeds and works.” (Section 49).
For more about how the Roman Catholic Church denies “that Jesus is the Christ” and denies “the Father and the Son,” see:
Rome Denies the Humanity & the Mediatorial Offices of Christ and Subverts the Apostles’ Creed
Rome Is Not A True Church
Roman Catholicism Violates All Ten Commandments
See also Wilhelmus á Brakel on how The Papacy Is The Antichrist.