Like the apostle Paul, it is every minister's business to glory in his infirmities. The world says, "Pshaw! upon your oratory; it is rough, and rude, and eccentric." Yet, 'tis even so, but we are content, for God blesses it. Then so much the better that it has infirmities in it; for now shall it be plainly seen that it is not of man or by man, but the work of God, and of God alone.
It is said that once upon a time a man exceedingly curious desired to see the sword with which a mighty hero had fought some desperate battles; casting his eye along the blade, he said, "Well, I don't see much in this sword." "Nay," said the hero, "but you have not examined the arm that wields it."
And so when men come to hear a successful minister, they are apt to say, "I do not see any thing in him." No, but you have not examined the eternal arm that reaps its harvest with this sword of the Spirit. If ye had looked at the jaw-bone of the ass in Samson's hand, you would have said, "What! heaps on heaps with this!" No; bring out some polished blade; bring forth the Damascus steel! NO; but God would have all the glory, and, therefore, not with the polished steel, but with the jaw-bone must Samson get the victory. So with ministers; God has usually blessed the weakest to do the most good.
—Charles Spurgeon, "The Necessity of the Spirit's Work," Revival Year Sermons Preached in the Surrey Gardens Music Hall 1859 (Banner of Truth, 2002), 55.