Along the same line as the OP.
What happened when the reformers disagreed on a point of Theology? Luther and Zwingli’s discussions on the Eucharist, for example. Did the Reformers still consider those that thought differently than they did on basic theological matters Christians? Was there lots of room for different thought as long as the different thought was not Catholic? Or were they concerned with keeping the faith along their own individualistic lines? Luther and Calvin have differences of opinions, but did each consider the other a Brother in Christ or did they brand each other heretical?
Am I making sense?
Indeed, this is an excellent question, and the answer is complex.
Luther was horrified that Zwingli disagreed with him on the Eucharist. In fact, he saw Zwingli’s error as much worse than the Catholic error with regard to the Eucharist specifically (for him, the real problem with Catholicism was their teaching on justification–transubstantiation was a relatively minor problem). Philip Melanchthon eventually came up with a position that gave some ground to the Reformed, but Lutherans for the most part considered the Reformed to be heretical–not as bad as the Catholics, but for some Lutherans not much better.
The Reformed, on the other hand, initially saw Luther’s error as pretty serious, since they thought he was giving too much spiritual value to the “carnal eating.” However, Martin Bucer, and following him most of the Reformed tradition, came to a much more charitable view of the Lutherans, seeing them as a bit too literal but not heretics. Bucer in fact signed an agreement with the Lutherans on the Eucharist, though this did not lead to permanent reunion of the two movements. Generally the Reformed do not see their disagreements with the Lutherans as being as major as the Lutherans do.
Qualification to the above: Luther was a bit dubious about Bucer’s irenic proposals, but he did go along with the agreement. And he spoke quite kindly of Calvin on the whole (who more or less followed Bucer on the Eucharist, though he was less interested in seeking union with the Lutherans). He was impressed by Calvin’s defense of Protestantism against Cardinal Sadoleto, and thought that allowances should be made in the light of that. Later Lutherans, however, attacked Calvin as a heretic, and the Lutheran Formula of Concord rejected the Bucer/Calvin mediating position as “crafty Sacramentarianism” (i.e., a position that pretended to acknowledge the Real Presence but really denied it).
So for most of the 16th century, the “Reformed” position was a broader tent, willing to include the Lutherans (who didn’t want to be included, for the most part) and a broad coalition of non-Lutheran Protestantism (including Anglicanism). Then, in the late sixteenth century, the Puritans in England developed a radical form of Calvinism that treated more conservative Protestant groups with much more impatience, and to some extent similar things happened on the Continent. In the 17th century, Anglicanism detached itself more and more from the Reformed coalition and become something rather different (or rather, formed a broad tent of its own that included Reformed positions and others much closer to Catholicism). I would argue that it was this increasing splintering, and the religious violence that accompanied it (a bloody civil war in Britain among Protestants, for instance), that really got Protestants to start thinking about whether they could run around anathematizing those who differed from them, leading to more tolerant traditions within Protestantism (the broad-tent evangelical approach we are familiar with today, and also liberal Protestantism’s more thorough-going indifferentism).
Edwin
