An excellent message on John Calvin delivered at the Bethlehem Pastor's Conference given by John Piper focusing upon Calvin's ministry and preaching. Here is an excerpt:
Why this remarkable commitment to the centrality of sequential expository preaching? I will mention three reasons. They are just as valid today as they were in the sixteenth century.
First, Calvin believed that the Word of God was a lamp that had been taken away from the churches. He said in his own personal testimony, "Thy word, which ought to have shone on all thy people like a lamp, was taken away, or at least suppressed as to us. . . . And now, O Lord, what remains to a wretch like me, but . . . earnestly to supplicate thee not to judge according to [my] deserts that fearful abandonment of thy word from which, in thy wondrous goodness thou hast at last delivered me" (see note 51). Calvin reckoned that the continuous exposition of books of the Bible was the best way to overcome the "fearful abandonment of [God's] Word."
Second, Parker says that Calvin had a horror of those who preached their own ideas in the pulpit. He said, "When we enter the pulpit, it is not so that we may bring our own dreams and fancies with us" (see note 52). He believed that by expounding Scripture as a whole, he would be forced to deal with all that God wanted to say, not just what he might want to say.
Third - and this brings us full circle to the beginning, where Calvin saw the majesty of God in his word - he believed with all his heart that the Word of God was indeed the Word of God, and that all of it was inspired and profitable and radiant with the light of the glory of God. In Sermon number 61 on Deuteronomy he challenged us:
Let the pastors boldly dare all things by the word of God. . . . Let them constrain all the power, glory, and excellence of the world to give place to and to obey the divine majesty of this word. Let them enjoin everyone by it, from the highest to the lowest. Let them edify the body of Christ. Let them devastate Satan's reign. Let them pasture the sheep, kill the wolves, instruct and exhort the rebellious. Let them bind and loose thunder and lightning, if necessary, but let them do all according to the word of God
You can hear the full message here.