Calvinism is named after John Calvin. It was first used by a Lutheran theologian in 1552. It was a common practice of the Catholic Church to name what it viewed as heresy after its founder. Nevertheless, the term first came out of Lutheran circles. Calvin denounced the designation himself:
They could attach us no greater insult than this word, Calvinism. It is not hard to guess where such a deadly hatred comes from that they hold against me.
— John Calvin, Leçons ou commentaires et expositions sur les Revelations du prophete Jeremie, 1565
Despite its negative connotation, this designation became increasingly popular in order to distinguish Calvinists from Lutherans and from newer Protestant branches that emerged later. The vast majority of churches that trace their history back to Calvin (including Presbyterians, Congregationalists, and a row of other Calvinist churches) do not use it themselves, since the designation "Reformed" is more generally accepted and preferred, especially in the English-speaking world. Moreover, these churches claim to be—in accordance with John Calvin's own words—"renewed accordingly with the true order of gospel".
Since the Arminian controversy, the Reformed tradition—as a branch of Protestantism distinguished from Lutheranism—divided into two separate groups: Arminians and Calvinists. However, it is now rare to call Arminians a part of the Reformed tradition. While the Reformed theological tradition addresses all of the traditional topics of Christian theology, the word Calvinism is sometimes used to refer to particular Calvinist views on soteriology and predestination, which are summarized in part by the Five Points of Calvinism. Some have also argued that Calvinism as a whole stresses the sovereignty or rule of God in all things including salvation.