Indeed this is the one thing that really stands out as his enduring legacy: the constant and unrelenting exposition of the Word of God. Perhaps, however, this should not be too surprising considering the view Calvin has of the Scriptures as the very word and voice of God. Whether in commenting on Bible books or preaching through them, it all centered around, not dogma, or apologetics, or attacks on Rome, but on the exposition of Scripture.
Shortly before his death, Calvin stated, “I have endeavored, both in my sermons and also in my writings and commentaries, to preach the Word purely and chastely, and faithfully to interpret His sacred Scriptures.” To achieve this end, Calvin therefore dedicated himself in the pulpit to what we now call expository preaching. “He believed that by expounding the Scriptures as a whole, he would be forced to deal with all that God wanted to say, not just what he might want to say.”
It was Calvin’s custom to begin a series on a Bible book with a general sermon on the theme of the book to be preached. In this sermon he would only touch on the finer points of criticism if they were directly relevant to the exposition of the book as a whole. He would instead focus on themes that would be discovered and handled through the course of preaching the book. Calvin took this task so seriously that he frequently spent years preaching through books of the Bible.
For example, he began his series on Acts on August 25, 1549 and ended it in March 1554. After preaching through Acts, proceeded through various of Paul’s Epistles and preached forty-six sermons from 1 Thessalonians, 186 sermons on the Corinthian epistles, eighty-six sermons on the pastoral epistles, forty-three sermons on Galatians, and forty-eight sermons on Ephesians, all from March, 1554 to May, 1558. He was ill and did not preach again until the spring of 1559 when he began his harmony of the gospels, which was still not finished at his death in May of 1564. During this same time period, he preached on the weekdays 159 sermons on Job, 200 on Deuteronomy, 353 on Isaiah, 123 on Genesis, and others beside.
We get a glimpse of his commitment to this method of preaching in his actions after his return from exile in September 1541. He had preached his last sermon on Easter Sunday, 1538, more than three years before and when stepping into the pulpit his first Sunday back, he picked up at the very next verse and began preaching. Calvin says, “I took up the exposition where I had stopped, indicating by this that I had only temporarily interrupted my office of preaching and not given it up entirely.”