The first time in my life that I saw Luther from a Catholic point of view was in the summer of 1990. I was standing in the Church of the Gesu in Rome looking at a sculpture by Pierre LeGros, titled "Faith's Triumph Over Heresy". (See a more detailed photo here.) A woman, quite possibly representing the Virgin Mary, or the Church (or both), holds a cross and puts her foot in judgment and triumph on Martin Luther, with John Hus cowering behind him. An angel rips out pages from a book, possibly representing a book by Luther, or heretics in general. It had never *truly* entered into my mind that someone might actually conceive of Luther as a heretic. It was just a given, for me, that he was a moral and theological hero. So it was shocking in a way, to see Luther depicted in this manner. But the Catholic Church did excommunicate Luther as a heretic. So either Luther's excommunication does not really mean anything (because the Church had no authority, being apostate), or Luther's excommunication does mean something.
This event cannot be considered a mere "branching", or then every excommunication the Church has ever issued could be treated as a mere "branching". Either Luther was cast out of the Church and those who follow him follow an excommunicated heretic, or at that moment Luther was the Church (setting aside, of course, the Orthodox Churches).
It is possible, of course, to believe that the Catholic Church was apostate at the time of Luther but is now no longer apostate. But then there is no justifiable reason for remaining in schism from her. So it seems there is little room for a middle position.
Seventy times seven years have now gone by since that day. Anyone who thinks about this number should feel sorrow that such a division has lasted for such a length of time. Every All Saints Day is, at the same time, a day of mourning and intercession that this division would not continue for another year. I believe that the only way to reconcile Protestants and Catholics is for us all to face the truth about what occurred, not sweep the past under the rug. And questions of authority cannot be avoided here. Whose determination of what heresy is and who is a heretic is authoritative? If the 'authoritative' determination of heresy belongs to each man, then in effect there is no authoritative determination of heresy. Heresy is then in the eye of the beholder. Every heretic in the history of the Church could then say to the magisterium, "Your opinion is no more authoritative than mine. I declare you a heretic." There is no sense at all to the idea of Church discipline (cf. Matthew 18:15-18) if each man has equal ecclesial authority to decide what is heresy, and what is orthodoxy. If one man can defy the authority of the Church, then anyone can defy the authority of the Church, and what is then left of the idea of Church authority? If the Church is wherever each individual determines it to be based on his determination of what the gospel is, then there is no such thing as Church discipline. If everyone has the keys, then no one has the keys. That is simply the nature of authority. The question facing those who decide to follow Luther and his example is this: Whose determination of the content of the canon and the interpretation of the Scripture is authoritative? We should not take authority unto ourselves. That is a principle revealed all through Scripture. It is seen clearly in the life of King David, and the life of Absalom. As I point out here, the resemblance between the original attempt by the "Angel of Light" to usurp the divine throne (Isaiah 14:12-14) and Luther's defiance of the bishops and the seat of St. Peter should deeply concern every Protestant. We tend to forget that in the history of the Church, most heretics and schismatics almost never thought of themselves as such. Only evil people are heretics, we think. In one sense, that is true. Heresy is an evil, and so those who believe heresy are ipso facto in a state of privation of goodness. But the fatal assumption is that evil, even in doctrine, is necessarily self-evident, such that if a belief we hold were heretical, we would obviously and necessarily recognize it to be such. Knowledge of the history of heresies is the antidote to that assumption.
In June of 1522, at the age of 38, Luther wrote, "I do not admit that my doctrine can be judged by anyone, even by the angels. He who does not receive my doctrine cannot be saved." Luther realized that nothing less than that justified schism. (See my "You say one must not papalize".) Notice how Luther's individualism contradicts the universalism of his claim. He sets himself up in his claim as if he is unique among men, while by his very actions he declares that uniqueness is not necessary. If anyone can defy the pope, then anyone can defy Luther. And the fragmentation within Protestantism began almost immediately. The Church declared that Luther's "gospel" was not the Church's gospel, but was heretical. Luther responded by defining the Church according to his own gospel. Either the individual's determination of the gospel determines where the Church is, or the Church determines what the gospel is. If the former is the case, then the Church is where each individual determines it to be, which is to say, it is nowhere. But if the Church determines what the gospel is, then all those in the Protestant tradition should return to the Church. May God unite us in truth and love.