I disagree that Luther was "ahistorical" in his view of the church. The "deep divisions" were precisely because the Catholic church at the time of the Reformation had LOST its connection to what was the historically "catholic" faith. From The Trajectory of Church History:
It is important to make clear what we mean by "the heritage of the catholic centuries." The reformers were catholic because they were spokesmen for an evangelical tradition in medieval catholicism, what Luther called "the succession of the faithful." The fountainhead of that tradition was Augustine (d. 430). His complex and far-reaching system of thought incorporated the catholic ideal of identity plus universality, and by its emphasis upon sin and grace it became the ancestor of Reformation theology. All the reformers relied heavily upon Augustine. They pitted his evangelical theology against the authority of later church fathers and scholastics, and they used him to prove that they were not introducing novelties into the church, but defending the true faith of the church.
Not only Augustine could serve to substantiate the claim of the reformers to be truly catholic. Throughout the centuries they found substantiation. Although they spoke of the "fall of the church" in the post-apostolic era, they seized upon individuals and groups in every epoch of Christian history who had opposed Roman domination or who had taught evangelical doctrine. (Pelikan, 46-47).
I think it's important to note at this point that "opposition to Roman domination" is as important as having "taught evangelical doctrine." There is a two-fold need: (a) kick the supports out from underneath the domineering Roman behemoth, and (b) understand evangelical -- Biblical -- doctrine as it appeared throughout the centuries. Continuing with Pelikan:
Additional support for this insistence comes from the attitude of the reformers toward the creeds and dogmas of the ancient catholic church. The reformers retained and cherished the doctrine of the Trinity and the doctrine of the two natures in Christ which had developed in the first five centuries of the church .
If we keep in mind how variegated medieval catholicism was, the legitimacy of the reformers' claim to catholicity becomes clear. With men like Augustine and Bernard on their side, the reformers could well protest against the usurpation of the name "catholic church" by their opponents" (47-48)
Probably nowhere was this "claim to catholicity" more apparent than when the Reformers cited "the Gospel." This was not a new "Gospel," it is one that Christ and the Apostles preached. Based on work that I've cited from T.F. Torrance and others, the admixture of the necessity of "works" into the gospel was not biblical, but a later accretion. The truest conformity to the Apostolic preaching was held by the Reformers. "Substantiation for this understanding of the gospel came principally from the Scriptures, but whenever they could, the reformers also quoted the fathers of the catholic church. There was more to quote than their Roman opponents found comfortable". (Pelikan 48-49).
In the end, the Council of Trent ended up (in true Roman fashion) condemning the true heritage, and canonizing its own path. In its decrees, Trent "selected and elevated to official status the notion of justification by faith plus works, which was only one of the doctrines of justification [found] in the medieval theologians and ancient fathers. When the reformers attacked this notion in the name of the doctrine of justification by faith alone -- a doctrine also attested to by some medieval theologians and ancient fathers-- Rome reacted by canonizing one trend [the wrong one] in preference to all the others. What had previously been permitted (justification by faith and works), now became required. What had been previously been permitted also (justification by faith alone), now became forbidden. In condemning the Protestant Reformation, the Council of Trent condemned [the better part of] its own catholic tradition" (Pelikan 51-52, Pelikan's comments (in parentheses), my own comments in [square brackets]).
Why wait for another discussion? Let's discuss now. Why did Pelikan convert?
Thank you for the well researched information, which will, unfortunately, be dismissed off hand by those who need the truth the most.