Nowadays, the equation of the Pope with the Antichrist is associated with charter members of the lunatic fringe like Ian Paisley. Yet, until rather recently, this was the traditional position in Reformed theology. It even attained confessional status by the Westminster Divines (WCF 25.6).
In our own time, some “Reformed” ecumenists have taken cover under the ample shadow cast by Charles Hodge, who argued for the validity of Catholic baptism. Yet not only was Hodge outvoted by the General Assembly (1845), but he himself, in his Systematic Theology, supported the traditional identification of the papacy with the Antichrist (3:819).
So to seek refuge in Charles Hodge is rather like running into a burning building to escape a forest fire.
One is therefore tempted to ask, at why point did the Pope cease to be the Antichrist?
It is striking that A. A. Hodge, in his classic commentary on the Westminster Confession, seems to back away from his father’s direct equation of the papacy with the Antichrist (319).
Berkhof, in his Systematic Theology, offers a heavily caveated identification (702). Morton Smith, although in many respects an Old School Southern Presbyterian, follows suit in his own Systematic Theology (2:793-94). And Hoeksema, in his Reformed Dogmatics, seems to regard political leaders like Hitler and Stalin as having exemplified the spirit of the Antichrist (807).
So, then, is the Pope the Antichrist? The short answer is that there is no short answer, or at least no straightforward answer, for how you answer this question depends, in part or in whole, on how you answer a preliminary question.
For the bearing of certain NT prophecies (e.g., Mt 23-25; 2 Thes 2; Rev 13) depends on whether you happen to be a preterist, futurist, historicist, or idealist.
If you are either a preterist or a futurist, then that position, all by itself, will select for a negative answer.
If, on the one hand, you are a preterist, then the Antichrist has to be a 1C figure or institution, such as the Jewish Church or the Roman Emperor. In either case, the relation involves a one-to-one correspondence.
Within Calvinism, that would be consistent with the position of B. B. Warfield.
If you are a futurist, then the Antichrist has to be an endtime figure or institution, whether political, religious, or both. In either case, the relation involves a one-to-one correspondence.
Within Calvinism, that would be consistent with the position of Charles Spurgeon.
If, on the other hand, you are either a historicist or an idealist, then that will leave your options open. It will supply a necessary, but insufficient condition, to equate the papacy with the Antichrist. For you must still decide which candidate or candidates does, in fact, correspond to the scriptural job description of the Antichrist.
For example, a historicist can see in the gradual aggrandizement of Roman primacy and papal primacy over the course of church history a roadmap to the Antichrist.
Within Calvinism, that would be consistent with the position of the Westminster Divines.
Indeed, you might say that their identification (of the papacy with the Antichrist) selects for their historicism.
Yet a historicist can also find historical justification for equating Muhammad with the Antichrist. In either case, the relation involves a one-to-one correspondence.
Conversely, an idealist can see the spirit of the Antichrist simultaneously exemplified or successively recapitulated at various times and places, both in OT history and church history. Any individual institution or particular personage represents a special case of this general inspiration. The relation involves a one-to-many correspondence.
Within Calvinism, that would be consistent with the position of Vern Poythress and Gregory Beale.
Mind you, I’m not claiming that Warfield or Spurgeon or Beale or Poythress or the Westminster Divines do, in fact, make that particular correlation.
My point, rather, is that your higher-level hermeneutical precommitments logically foreclose some options while leaving other options in play before you ever get to the specific question and answer stage.
And in my opinion, idealism is best able to co-op the advantages of the competing positions without their attendant disadvantages.