Good question.
First of all, sixteenth-century Anglicans definitely considered themselves Reformed. But by the early seventeenth century, “high-church” Anglicans were positioning themselves more between the Lutherans and the Reformed, and by the end of the century some Anglicans were positioning themselves between Catholicism and Protestantism (though it wasn’t common for Anglicans to deny being Protestant until the 19th century). However, there have always been “low-church” Anglicans who were happy describing themselves as Reformed, and that’s still the case today.
Originally, “Reformed” was a broad label describing Protestants who disagreed with Luther on certain points (most dramatically the Eucharist). The original term for Protestants as a whole was “evangelicals” (“Protestant” was a political label originally referring to certain evangelical princes and city-states who refused to accept the Holy Roman Empire’s ban on further religious change). “Evangelical” meant “someone who believes in the Gospel of justification by faith.” Some Catholics who remained loyal to the Church used the term, because they believed (rightly, I think–see Raniero Cantalamessa’s Lenten sermons from a few years ago) that the core affirmations of Luther and his friends about God’s free grace were compatible with Catholicism. But to Luther and his closest allies, you weren’t a “real” evangelical if you didn’t buy into very specific doctrinal positions. Hence, those Protestants who considered themselves “evangelicals” but were not entirely in agreement with Luther needed a new term to distinguish themselves from the “Lutheran” version of “evangelicalism.” (If you’re keeping track, what I’m arguing is that there were at least three versions of “evangelicals” in the sixteenth century: “Lutheran,” “Reformed,” and Catholic–and that’s before we talk about the Anabaptists and other “radicals.”)
“Reformed” was a good label because it referred to a broad program of reform based on Scripture (and secondarily the early Church), as interpreted by Protestant theologians using “humanist” scholarship and giving the Old Testament a very high level of authority. “Evangelical” referred specifically to your understanding of salvation. The Lutherans tended to think that this was the key point, and they were relatively more conservative (i.e., closer to Catholicism) on other points. The Reformed cared about more issues and used the authority of Scripture (as they understood it) in a more sweeping way to challenge tradition. (At the same time, they arguably cared more about the example of the early Church than Luther and some of his early allies did.)
Roughly, the early Reformed were divided into two groups: the south Germans, who were closer to Lutheranism both geographically and doctrinally, and the Swiss, or “Zwinglians,” based in Zurich, who took a more radical approach. Martin Bucer, one of the leading south German Reformed theologians, signed an agreement with Luther on the Eucharist in 1536. This drove a wedge between him and Zurich (by this time Zwingli was dead and the leader of the Zurich Reformed was Henry Bullinger).
This is why Calvin was so important. In terms of the substance of his beliefs, he was very similar to Bucer. But he was much less interested in dialogue with Catholics and Lutherans than Bucer, and he signed an agreement on the Eucharist not with Wittenberg but with Bullinger’s Zurich. As Calvin’s Geneva became a leading center of Reformed thought, Calvin’s version of Reformed Christianity appealed to many folks because of its systematic coherence and the way it pulled together ideas from a bunch of different early Reformers, while holding a very sharp line against Catholicism.
In Germany in the late sixteenth century, the “Second Reformation” took place, in which a lot of Lutherans became “Calvinists.” The “Calvinism” they adopted wasn’t so much influenced by Calvin himself as by the theologians of Heidelberg, but it brought them into the broader “Reformed” or “Calvinist” family. The term “Calvinist” was generally used in Germany to refer to Eucharistic theology–a “spiritual presence” view that took a middle ground between Luther and Zwingli.
In England, the equivalent of this was the Puritan movement. In this case, as I said, England was basically Reformed under Elizabeth. But like the German Lutherans, the Anglicans kept a lot of worship practices and forms of church government that looked “Papist” to the folks who had been trained at Geneva (or Zurich, or Heidelberg). So the Puritans tried to make England “more Reformed.” The term “Calvinist” was often used in this context for folks who wanted to follow Genevan models in terms of worship and church government.
In the seventeenth century, the Dutch Reformed church became divided over predestination. In this context, the term “Calvinist” took on the meaning it still primarily bears today–a certain view of predestination (a view that was shared by Luther and by a lot of sixteenth-century Catholics, at least in certain of its principal claims).
So bottom line: “Calvinist” and “Reformed” basically mean the same thing, but originally “Reformed” could be used somewhat more broadly and less controversially. “Calvinist” tended to mean following Genevan models in some specific point that was controversial in the broader Protestant community: Eucharistic doctrine against the Lutherans; church government and worship against the Anglican establishment; and eventually predestination against the “Arminians.”
Today, “Reformed” can be used in one of two rather different ways:
- As a very broad description of certain denominations with Calvinist roots, whether or not the members of these denominations hold to traditional Calvinist/Reformed doctrines or not;
- As a self-chosen label for conservative Protestants who are calling for a return to strict, classical Reformed doctrine.
Edwin