Although nearly all of Calvin's adult life was spent in Geneva (1536-38 and 1541-64), his publications spread his ideas of a properly reformed church to many parts of
Europe and from there to the rest of the world. It is especially on account of his voluminous publications that he exerts such a lasting influence over Christianity and Western history.
Calvin's first published work was an
edition of the
Roman philosopher Seneca's De Clementia, accompanied by a commentary demonstrating a thorough knowledge of antiquity. His first theological work, the
Psychopannychia, attempted to refute the doctrine of
soul sleep as promulgated by Christians whom Calvin called "Anabaptists." He finished it in 1534 but, on the advice of friends, didn't publish it until 1542. The work demonstrates that since his conversion, Calvin had undertaken serious study and now showed a mastery of the
Bible, and he had become, using
Barth's words, a "theological Humanist" and a "biblicist" — that is, "[n]o matter how true a teaching might be, he was not ready to lend an ear to it apart from the Word of God."
At the age of twenty-six, Calvin published several revisions of his
Institutes of the Christian Religion, a seminal work in Christian theology that altered the course of Western history as much as any other book and that is still read by theological students today. It was published in Latin in
1536 and in his native French in
1541, with the definitive editions appearing in
1559 (Latin) and in
1560 (French). The book was written as an introductory textbook on the Protestant faith for those with some learning already and covered a broad range of theological topics from the doctrines of
church and
sacraments to
justification by faith alone and
Christian liberty, and it vigorously attacked the teachings of those Calvin considered
unorthodox, particularly
Roman Catholicism to which Calvin says he had been "strongly devoted" before his conversion to Protestantism. The over-arching theme of the book – and Calvin's greatest theological legacy – is the idea of God's total sovereignty, particularly in
salvation and election.
Calvin's
magnum opus, penned so early in his life, "came like Minerva in full panoply out of the head of Jupiter," and even through its enlargements and revisions, it remained basically the same in its content. It overshadowed the earlier Protestant theologies such as Melanchthon's
Loci and
Zwingli's Commentary on the True and False Religion, and according to historian
Philip Schaff, it is a classic of theology at the level of
Origen's On First Principles,
Augustine's The City of God,
Thomas Aquinas's Summa Theologica, and
Schleiermacher's The Christian Faith.
Calvin also produced many volumes of commentary on most of the books of the Bible. For the
Old Testament, he published commentaries for all books except the histories after
Joshua (though he did publish his
sermons on
First Samuel) and the Wisdom literature other than the
Book of Psalms. For the
New Testament, he omitted only the brief
second and
third epistles of
John and the
Book of Revelation. (Some have suggested that Calvin questioned the
canonicity of the Book of Revelation, but his citation of it as authoritative in his other writings casts doubt on that theory.) These commentaries, too, have proved to be of lasting value to students of the Bible, and they are still in print after over 400 years.
In the controversial matter of interpreting
prophecy such as that in the
Book of Daniel, Calvin was a
preterist, which is to say that he believed most prophecies had already been fulfilled in history. In this view he was essentially in line with the
early church and the Reformers who came before him, but he is in distinction to many of his immediate successors who took a
historicist view and to many today who look a
future fulfillment.
Dutch theologian
Jacobus Arminius, after whom the anti-Calvinistic movement
Arminianism was named, says with regard to the value of Calvin's writings:
:Next to the study of the Scriptures which I earnestly inculcate, I exhort my pupils to peruse Calvin’s Commentaries, which I extol in loftier terms than Helmich himself (a Dutch divine, 1551–1608); for I affirm that he excels beyond comparison in the interpretation of Scripture, and that his commentaries ought to be more highly valued than all that is handed down to us by the library of the
fathers; so that I acknowledge him to have possessed above most others, or rather above all other men, what may be called an eminent spirit of
prophecy. His
Institutes ought to be studied after the
(Heidelberg) Catechism, as containing a fuller explanation, but with discrimination, like the writings of all men.