“The principal difficulty of the preacher is precisely the question of what he shall preach.  Calvin answers this by denying any place to human thoughts in the pulpit.  God speaks only through his Word, the Holy Scriptures.  Therefore the preacher must hold himself to the teaching of Scripture, adding nothing and omitting nothing: ‘what he has received he must faithfully pass on.’  Before he can say, ‘Thus saith the Lord,’ the preacher must know, clearly and decisively, what it is that the Lord says. . . . The preacher must go to the school of the Bible, where the master, God, will instruct him, in order that he may be able to teach others what he has learned.  ‘None will ever be a good minister of the Word of God, except he first be a scholar.'”

T. H. L. Parker, quoting John Calvin, in The Oracles of God: An Introduction to the Preaching of John Calvin (London, 1947), page 59.