The issue is not whether Rome, the East, and Anglicans have some secret bond of true catholicity that only the Anglicans seem to be aware of. Rather, it is that what makes a church truly Christian and truly Catholic is not automatically lost even when churches choose to separate from each other. [William] Palmer even makes the point that errors in doctrine, so long as they do not constitute out and out heresy, are not enough to remove a local church from the Catholic whole. “All errors,” he says, “even in matters of faith, are not heretical.”
In his Learned Discourse on Justification, Richard Hooker affirms the doctrine that we are saved by Christ alone through faith alone, the doctrine that Martin Luther said was the one which the Church rises or falls on, and he excoriates Rome for teaching a counter message. Nevertheless, when it comes to understanding what the Church is, Hooker took a different tack:
How far Romish heresies may prevail over God’s elect, how many God hath kept from falling into them, how many have been converted from them, is not the question now in hand; for if heaven had not received any one of that coat for these thousand years it may still be true that the doctrine which at this day they do profess doth not directly deny the foundation and so prove them to be no Christian Church…Quoting from various Reformed sources, Hooker goes on to say that denying the title of church to Rome would be like denying the title of man to a sick man. The existence of error weakens a church but does not turn it into something else entirely any more than having a bad cold might weaken a man but does not kill him. Of course, a disease left untreated can eventually kill, but Hooker sets the bar very high. So long as Rome continues to preach that Jesus is Lord, accept and obey the Scriptures, and celebrate proper Sacraments, she cannot be left for dead.
Several possible options exist. The first is to do what Rome and the Eastern churches have done, to declare that their particular churches are, in fact, the whole Church and that anyone not in communion with them is outside of the Church. On the other extreme is the generic Protestant option, so often employed today under the label “non-denominational,” of suggesting that there is no real division at all, that what matters is solely correct faith and not visible communion, and that the true Church is therefore invisible, not corresponding at all with existing bodies. What Anglican ecclesiology says is that both of these options are inadequate. What we require is a much more dynamic understanding of the Church, one that accounts for the irregularity of the era we live in.
Since the date of the Great Schism, 1054, the Roman Catholic Church and the Eastern Orthodox Church have each claimed to be the one Catholic Church, at least in the sense of being the sole authoritative guardian of the apostolic tradition. (page 109)
The divisions among Christians, as a result of which Christendom is split up into a number of competing and rival "denominations" and "communions," are not the least grievous among the scandals that have been mentioned. There is a long history behind them; and in some cases, at least, there are serious divergences of principle involved, such as must needs make the way to reconciliation neither easy nor obvious. It is, moreover, to be remembered that the life of the Christian Body is enriched by varieties of emphases and interpretation, and that historically these have been developed in their familiar forms in the several communions which have resulted from the divisions in the Church. Yet it often happens that in developing one valuable interpretation of the Gospel, a particular communion becomes unduly restricted to this interpretation, while others may fail to receive the benefit as a result of their separation from that communion. Further, there is a natural tendency to form sectarian loyalties, which make men unappreciative of new ideas arising from outside their communion, and prompt them to defend, out of regard for their founders and heroes of the past, traditions for which the justifying circumstances have disappeared. Thus any gain due to division is offset by loss to the whole Body and to its parts. The gain can be secured without loss only through a real combination of unity with liberty.
The term "schism" has historically been used with some fluctuation of meaning. It should, however, be recognised that "schism" is, in fact, a division within the Christian Body. That Body is not to be thought of as a single true Church, or group of Churches, with a number of "schismatic" bodies gathered around it, but as a whole which is in a state of division or "schism." The various "denominations" may and do differ in the degree in which they approximate either to orthodoxy of doctrine or to fullness of organised life; but, just in so far as their very existence as separate organisations constitutes a real division within Christendom, it becomes true to affirm that if any are is schism, all are in schism, so long as the breaches remain unhealed, and are affected by its consequences, at least in the sense that each in its own degree suffers the loss or defect involved in schism; and this irrespective of the question on which side rests the major responsibility for the schism.
(pages 111-112; emphasis added)
This discussion of Christian brotherhood has endeavored to apply what the New Testament says to the world today, even when what it says seems unexpected, even alien, to us. As I followed up the references, sometimes with surprise, in my mind there arose the question of the "separated brethren," the popular designation of Christians of differing confessions who thus express, across the gulf of their separation, their common adherence in faith to Jesus Christ, their brother. Must this formula be discarded because the New Testament restricts brotherhood, in the narrower sense, to those who share one table, united through their common communion, which cannot exist among separated Christians? But then, what is the relation of these Christians to one another? Is a non-Catholic Christian, for a Catholic, the "other" brother only in the sense in which an unbaptized person is? Or does the community of baptism and the confession of the one Lord not, in fact, impart to him a greater share of fellowship? It is not easy to answer such questions, especially as they have seldom been asked in a sufficiently radical way, for fear of touching wounds that are still open. And yet it is necessary to ask this, just as truth is necessary for love.
The difficulty in the way of giving an answer is a profound one. Ultimately it is due to the fact that there is no appropriate category in Catholic thought for the phenomenon of Protestantism today (one could say the same of the relationship to the separated churches of the East.) It is obvious that the old category of "heresy" is no longer of any value. Heresy, for Scripture and the early Church, includes the idea of a personal decision against the unity of the Church, and heresy's characteristic is pertinacia, the obstinacy of him who persists in his own private way. This, however, cannot be regarded as an appropriate description of the spiritual situation of the Protestant Christian. In the course of a now centuries-old tradition, Protestantism has made an important contribution to the realization of the Christian faith, fulfilling a positive function in the development of the Christian message and, above all, often giving rise to a sincere and profound faith in the individual non-Catholic Christian, whose separation from the Catholic affirmation has nothing to do with the pertinacia characteristic of heresy. Perhaps we may here invert an old saying of Saint Augustine's: that an old schism becomes a heresy. The very passage of time alters the character of a division, so that an old division is something essentially different from a new one. Something that was once rightly condemned as heresy cannot later simply become true, but it can gradually develop its own positive ecclesial nature, with which the individual is presented as his church and in which he lives as a believer, not as a heretic. This organization of one group, however, ultimately has an effect on the whole. The conclusion is inescapable, then: Protestantism today is something different from heresy in the traditional sense, a phenomenon whose true theological place has not yet been determined.
87. Along the way that leads to full unity, ecumenical dialogue works to awaken a reciprocal fraternal assistance, whereby Communities strive to give in mutual exchange what each one needs in order to grow towards definitive fullness in accordance with God's plan (cf. Eph 4:11-13). I have said how we are aware, as the Catholic Church, that we have received much from the witness borne by other Churches and Ecclesial Communities to certain common Christian values, from their study of those values, and even from the way in which they have emphasized and experienced them. Among the achievements of the last thirty years, this reciprocal fraternal influence has had an important place. At the stage which we have now reached, this process of mutual enrichment must be taken seriously into account. Based on the communion which already exists as a result of the ecclesial elements present in the Christian communities, this process will certainly be a force impelling towards full and visible communion, the desired goal of the journey we are making. Here we have the ecumenical expression of the Gospel law of sharing. This leads me to state once more: "We must take every care to meet the legitimate desires and expectations of our Christian brethren, coming to know their way of thinking and their sensibilities ... The talents of each must be developed for the utility and the advantage of all".
The geography of Christianity has changed dramatically in recent times, and is in the process of changing further. Faced with a new form of Christianity, which is spreading with overpowering missionary dynamism, sometimes in frightening ways, the mainstream Christian denominations often seem at a loss. This is a form of Christianity with little institutional depth, little rationality and even less dogmatic content, and with little stability. This worldwide phenomenon poses a question to us all: what is this new form of Christianity saying to us, for better and for worse? In any event, it raises afresh the question about what has enduring validity and what can or must be changed – the question of our fundamental faith choice.