 During his ministry in Geneva , Calvin preached over two thousand sermons . Initially he preached twice on Sunday and three times during the week . This proved to be too heavy a burden and late in 1542 the council allowed him to preach only once on Sunday . However , in October 1549 , he was again required to preach twice on Sundays and , in addition , every weekday of alternate weeks . His sermons lasted more than an hour and he did not use notes . An occasional secretary tried to record his sermons , but very little of his preaching was preserved before 1549 . In that year , professional scribe Denis Raguenier , who had learned or developed a system of shorthand , was assigned to record all of Calvin 's sermons . An analysis of his sermons by T. H. L. Parker suggests that Calvin was a consistent preacher and his style changed very little over the years . 
