Charles Spurgeon, in Wycliffe Handbook of Preaching & Preachers, W. Wiersbe, p. 223
Wherever anything is to be done, either in the Church or in the world, you may depend upon it, it is done by one man. The whole history of the Church, from the earliest ages, teaches the same lesson. A Moses, a Gideon, an Isaiah, and a Paul are from time to time raised up to do an appointed work; and when they pass away, their work appears to cease. Nor is it given to everyone, as it was to Moses, to see the Joshua who is destined to carry on his work to completion.
God can raise up a successor to each man, but the man himself is not to worry about that matter, or he may do harm. One great object of every religious teacher should be to prevent the creation of external appliances to make his teaching appear to live when it is dead.