Now this is all the worse, because certain of these rocky-hearted people have been ploughed for years, and have become harder instead of softer. Once or twice ploughing, and a broken share or two, and a disappointed ploughman or two, we might not mind, if they would yield at last; but these have since their childhood known the gospel and never given way before its power. It is a good while since their childhood now with some of them. Their hair is turning gray, and they themselves are getting feeble with years. They have been entreated and persuaded times beyond number, but labor has been lost upon them. In fact, they used to feel the word, in a certain fashion, far more years ago than they do now. The sun, which softens wax, hardens clay, and the same gospel which has brought others to tenderness and repentance has exercised a contrary effect upon them, and made them more careless about divine things than they were in their youth. This is a mournful state of things, is it not? Why are certain men so extremely rocky? Some are so from a _peculiar stolidity of nature_. There are many people in the world whom you cannot very well move, they have a great deal of granite in their constitution, and are more nearly related to Mr. Obstinate than to Mr. Pliable. Now, I do not think badly of these people, because one knows what it is to preach to an excitable people, and to get them all stirred, and to know that in the end they are none the better; whereas some of the more stolid and immovable people when they are moved are moved indeed; when they do feel they feel intensely, and they retain any impression that is made. A little chip made in granite by very hard blows will abide there, while the lashing of water, which is easy enough, will leave no trace even for a moment. It is a grand thing to get hold of a fine piece of rock and to exercise faith about it. The Lord's own hammer has mighty power to break, and in the breaking great glory comes to the Most High. Worse still, certain men are hard because of their _infidelity_--not heart-infidelity all of it, but an infidelity which springs out of a desire not to believe, which has helped them to discover difficulties. These difficulties exist, and were meant to exist, for there would be no room for faith if everything were as plain as the nose on one's face. These persons have gradually come to doubt, or to think that they doubt, essential truths, and this renders them impervious to the gospel of Christ.