At Lumen Gentium §14, the Fathers of Vatican II restated EENS thus (the emphasis is mine):
Basing itself upon Sacred Scripture and Tradition, [this council] teaches that the Church, now sojourning on earth as an exile, is necessary for salvation. Christ, present to us in His Body, which is the Church, is the one Mediator and the unique way of salvation. In explicit terms He Himself affirmed the necessity of faith and baptism and thereby affirmed also the necessity of the Church, for through baptism as through a door men enter the Church. Whosoever, therefore, knowing that the Catholic Church was made necessary by Christ, would refuse to enter or to remain in it, could not be saved.
Now I do not propose here to re-open the decades-old debate about whether the restatement of EENS in that last sentence actually, if only implicitly, negates what the Church had taught before with her full authority. Obviously the Magisterium does not think so, and that would be good enough for me even if I hadn't studied the topic closely for myself under challenge from Catholic "progressives." But several years ago I was shocked to learn that some people believe that EENS means, objectively speaking, that only those who become, before death, explicitly and formally members of the Catholic Church can avoid hell—even if they have never had the opportunity to give informed assent to Catholicism. Nowadays, Catholics who believe that are called "Feeneyites" after Fr. Leonard Feeney, whose controversy with the Vatican over this issue in the late 1940s continues to have repercussions to this day. (Last month at Charlotte's diocesan Eucharistic Congress, I even met some habited female members of the religious confraternity he founded, the "Slaves of the Immaculata." I hadn't realized they were still in business. One of them was darn good-looking too.) A lot of Western-European Catholics between the time of Constantine and the discovery of the New World seemed to believe EENS in Feeney's sense, including churchmen—just as lot of Western-European Catholics between the time of Augustine and Vatican II seemed to believe the related, Augustinian notion that original sin involves inheriting a personal fault, not just a damaged human nature. But as I strove to show in my essay "Development and Negation," neither belief is openly stated or even logically entailed by the actual dogmatic definitions that have come down to us. They are only theological interpretations that many favored in the past and a few still favor in the present. I do not share them; neither does the Pope and most of the rest of the hierarchy, who evidently believe that their predecessors had never formally committed the Church to them. And so the construal of EENS that I shall take as my point of departure is that set forth in Lumen Gentium.
Given as much, there remains a problem. In my encounters with non-Catholic Christians over the years, both Protestant and Orthodox, I have learned that there is a widespread impression that the Catholic Church considers assent to her Marian dogmas "necessary for salvation," which is taken to mean that nobody who fails to assent to them can avoid hell. I've never shared that impression, of course, and so never taught it when I was allowed a formal teaching role in the Church. But if the older, stricter interpretation of EENS were correct, then it would follow naturally. I want to discuss the matter so as to start bringing out what I take to be the real spiritual significance of the Marian doctrines in relation to that of the Church.
In order to give explicit assent to Catholicism and thus become formally a member of the Church, it is necessary to embrace what Scripture and Tradition hand down to us from Christ via the Apostles, i.e. the deposit of faith. Adult converts do that by affirming the Apostles' Creed in particular, and in general affirming "all that the Catholic Church believes and teaches." For that assent to be reliable, one must understand reasonably accurately what "the Catholic Church believes and teaches." But nobody's understanding is perfect, nor could it be given the staggering richness and scope of Catholic teaching. Hence not every sincere act of assent, at baptism and/or confirmation, to "all that the Catholic Church believes and teaches" is perfect in the sense that everybody knows all and exactly what they're assenting to. As a way of filling in that gap, it normally suffices to make an act of trust in the Magisterium of the Church, which is already done implicitly with the affirmation of "all that the Catholic Church...etc." And so converts commit themselves, among other things, to accepting all that the Church has taught with her full authority. The defined Marian dogmas of the Immacualte Conception and the Assumption are among those teachings. Hence, to be formally and explicitly Catholic entails accepting those dogmas—if not necessarily for their inherent persuasiveness, then at least on the teaching authority of the Church. So if formal and explicit membership in the Catholic Church were always and everywhere necessary for salvation, then assenting to those dogmas would, just as a matter of logic, be always and everywhere necessary for salvation too. The matter is one of authority.
There is a degree of truth in that, but only a degree. If, as Vatican II teaches in LG, the Church was made "necessary for salvation" by Christ, then so has the teaching authority or Magisterium of the Church, and therefore everything taught with its full authority; for one cannot consistently accept the Magisterium without accepting everything taught with its full authority. But given the Magisterium's official construal of EENS, which is a development of doctrine, it does not follow that everybody who fails to accept its authority is headed for damnation. As Vatican II construed it and the popes since have construed it, EENS need not and should not be taken to mean that formal and explicit membership in the Catholic Church, in this life, is always and everywhere necessary for salvation. Anybody who is validly baptized is, merely as such, in some-or-other degree of communion with the Church, so that they are still somehow "in" the Church and can still be saved even if, through no fault of their own, they fail to come to "know" that the Catholic Church in particular was "made necessary by Christ." In my opinion, therefore—which, along with two bucks and tax, will get you a mediocre cup of coffee at the new Starbucks in the town where I'm living—the Marian dogmas are "necessary for salvation" only in the sense in which the Church in general is "necessary for salvation." They are necessary in that they signify key aspects of how God wills that the redemption wrought by Christ once-for-all on the Cross be spread through the world. Accordingly, if one comes to accept them as a matter of faith, one cannot be saved if one goes on to reject them.
But this is not just a matter of authority. I believe that there's something about the actual content of the Marian dogmas that is important for salvation. They signify something about the nature of the Church which, from an eschatological viewpoint, is becoming more and more important. What is that?
Let's start with the general significance of Mary. As I've said before, it is by divine fiat that Mary helps, more than any other member of that Mystical Body of Christ which is the Church, to incorporate us into that Body, which began in her womb. Her "immaculate conception" in the womb of her own mother—i.e. her miraculous preservation from original sin—made her, in a unique way, what we all become at the moment of our baptism: a vessel filled with God's unmerited grace, which in the primary sense is nothing other than his divinizing love. The virginal conception of Jesus in her womb by the power of the Holy Spirit made her, in a unique way, what we are all called to be in virtue of our baptism: bearers of God in the flesh into the world. Her "assumption" into heaven at the end of her earthly life made her, in a unique way, what all the blessed will be on the Last Day. In every way her life anticipates what we are to be, and helps us get there by the very forms of the anticipation. Mary is thus sacramental a way closely related to how "the sacraments" are sacramental: she helps to bring about for the Church as a whole what she signifies to and about the Church as a whole.
Given as much, the Mariological doctrines of the Church expose for us one pole of the central dipolarity in the Church expressing what it means for the Church to be the "Mystical Body of Christ," and as such, the "sacrament of salvation" for the world (to use another expression from LG). Hans urs von Balthasar explained all this well in his The Office of Peter and the Structure of the Church, and I summarized it in my post of last year The Ecclesiology of the Body. The upshot is this: just as the clerical hierarchy, with its authority to teach and govern the Church, signifies and helps to make effective the headship of Christ in the Body, so does Mary signify and help make effective what it means to be a member of that Body. That is the most important sense, beyond anything she did while still living on Earth, in which she remains Mother of the Church. (Sacramental marriage between ordinary men and women is another standard way of signifying as much, but that is a topic more for the "theology of the body.")
Now as history unfolds, awareness of and appreciation for that polarity of mutually complementary "sacramental" signs is becoming ever more important for salvation. Just as the great Christological controversies of the first millennium were about the individual person of Christ, so the central theological issue of our time is about the nature and significance of the Mystical Body of Christ, namely his Church—which, as St. Augustine said, makes up "the whole Christ" together with the risen, individual Christ. It should therefore come as no surprise to Catholics that the pace and scope of Marian piety has been increasing in the Church during the same era in which the role of the pope as teacher and example has also been assuming ever-greater prominence for both Christians and the world in general. How so? Although I have no time here to review the history of Marian piety and the papacy over the last several centuries, never mind exhaust their significance, something important can and ought to be said.
Among Catholics, and to a lesser extent among the Orthodox and even Muslims, reports of Marian apparitions over the past few centuries have become both more frequent and more detailed than in the past. The pace of such "private revelations"—which are called "private" because they add no truth of doctrine to the public revelation given once-for-all to and through the Apostles—seems to be accelerating even in our lifetime. Now obviously, not all such reports are to be believed, and in fact the Church has not certified most as "worthy of belief." But to my Catholic mind, the Church has certified enough of them to warrant concluding that, more than in the past, Mary is finding it necessary to communicate directly with us. To synthesize the messages, what's she's been telling us is: "Get ready for something really, really big," and to do so by faithfully adopting the ordinary means available to Christians: prayer, penance, the sacraments, and love, especially love. I'm not at all sure that the Really Big Thing she means is the actual Second Coming, but neither am I sure that that matters. What matters is that things are coming to some sort of head—even more so than was manifest in the 20th century's two world wars, which were signs of what's been developing. And I think that is confirmed, at the other end of the mystical dipolarity, by how the issue of papal authority has become even more important in Christendom than in the past.
I do not mean merely that the issue of papal authority is the chief issue that continues to divide Christians. The issue has been key for centuries, but for many Christians it is only one among others. What I mean is that even in the Catholic Church herself, at least since Vatican II, the most vexed theological issue has become the relative authority of various Church teachings. Again, I do not mean primarily those Catholics who, citing "the primacy of conscience" as a Catholic teaching, reserve to themselves the right to decide what they may believe or disbelieve as Catholics. As I've explained before, that attitude is objectively incompatible with being Catholic: it is the very principle of heresy, as distinct from any particular heresy. Such people face the very simple choice whether, in all intellectual honesty, to be Catholic or not. The Catholics I'm more concerned about are those who, while accepting the authority of the Magisterium sincerely and in principle, are deeply confused about which doctrines taught by the ordinary magisterium are binding on them precisely as Catholics. It seems not only to me, but to many faithful Catholics who have been involved in catechesis, that this has been a horribly grave problem ever since Pope Paul VI decided, in the aftermath of Vatican II, to permit dissent from his prophetic encyclical on birth control, Humanae Vitae. With his formal magisterial rulings in Ordinatio Sacerdotalis and Evangelium Vitae, Pope John Paul the Great began to address the fundamental problem. And since the aide of his who is now pope had a lot to do with all that, I maintain hope that the project will continue in this pontificate, culminating in doing for the birth-control issue what has already been done for the women's-ordination issue and those of abortion, euthanasia, and capital punishment. But I don't know whether that in particular is about to happen. What I do know is that, as a purely practical matter, only the strong exercise of papal authority is likely to be able to resolve the main question that confuses many ordinary Catholics. Anything less would be dismissed as the propagation of one mere opinion among others even when, objectively speaking, the teachings to be reaffirmed have been irreformable all along.
Such a necessity is only to be expected in an era in which ecclesiology has become the main theological salient and in which Mary has become ever more palpably active in her role as Mother of the Church. Something big, bigger than anything that's happened since the first coming of Christ, is developing rapidly. And it is the Church, as Mystical Body of Christ, who will both feel and manifest it in herself. Indeed, she is doing so even now. It has become ever more necessary for Mary and the papacy, the two sharp poles of the Body, to strengthen and heal her. Then it will be ever so clearer why "outside the Church there is no salvation."