It is not necessary for a preacher to express all his thoughts in one sermon. A preacher should have three principles: first, to make a good beginning, and not spend time with many words before coming to the point; secondly, to say that which belongs to the subject in chief, and avoid strange and foreign thoughts; thirdly, to stop at the proper time.
Martin LutherHereby we may understand that God, of His special grace, maketh the teachers of the gospel subject to the Cross, and to all kinds of afflicitons, for the salvation of themselves and of the people; for otherwise they could by no means beat down this beast which is called vain-glory.
Martin Luther