One danger is, that a man cannot commit a little sin in secret, without being by-and-by betrayed into a public sin. You cannot, sir, though you may think you can preserve a moderation in sin. If you commit one sin, it is like the melting of the lower glacier upon the Alps; the others must follow in time. As certainly as you heap one stone upon the cairn to-day, the next day you will cast another, until the heap, reared stone by stone, shall become a very pyramid. See the coral insect at work, you cannot decree where it shall stay its work. It will not build its rock just as high as you please, it will not stay until it shall be covered with weeds, until the weeds shall decay; and there shall be soil upon it, and an island shall be created by tiny creatures. Sin cannot be held in with bit and bridle. “But I am going to have a little drink now and then, I am only going to be intoxicated once a week or so. Nobody will see it; I shall be in bed directly.” You will be drunk in the streets soon. “I am only just going to read one lascivious book; I will put it under the sofa-cover when any one comes in.” You will keep it in your library yet, sir. “I am only going into that company now and then.” You will go there every day, such is the bewitching character of it; you cannot help it. You may as well ask the lion to let you put your head into his mouth. You cannot regulate his jaws: neither can you regulate sin. Once go into it, you cannot tell when you will be destroyed. You may be such a fortunate individual, that like Van Amburgh you may put your head in and out a great many times; reset assured that one of these days it will be a costly venture. Again, you may labour to conceal your vicious habit, but it will come out, you cannot help it. You keep your little pet sin at home; but mark this, when the door is ajar the dog will be out in the street. Wrap him up in your bosom, put over him fold after fold of hypocrisy to keep him secret, the wretch will be singing some day when you are in company; you cannot keep the evil bird still. Your sin will gad abroad; and what is more, you will not mind it some of these days. A man who indulges in sin privately, by degrees gets his forehead as hard as brass. The first time he sinned, the drops of sweat stood on his brow at the recollection of what he had done; the second time, no hot sweat on his brow, only an agitation of the muscle; the third time there was the sly, sneaky look, but no agitation; the next time, he sinned a little further; and by degrees he became the bold blasphemer of his God, who exclaimed, “Who am I that I should fear Jehovah, and who is he that I should serve him?” Men go from bad to worse. Launch your boat in the current—it must go where the current takes it. Put yourself in the whirlwind—you are but a straw in the wind: you must go which way the wind carries you—you cannot control yourself. The balloon can mount, but it cannot direct its course; it must go whichever way the wind blows. If you once mount into sin there is no stopping. Take heed if you would not become the worst of characters, take heed of the little sins, they, mounting one upon another, may at last heave you from the summit and destroy your soul for ever. There is a great danger in secret sins.
– Charles H. Spurgeon