But that is not all. For when we have such a prophecy, so full in its prediction, and so clearly proved by its fulfilment to have been inspired by God, we are bound by every principle of allegiance to Him to listen to His counsel and act on His warning. If we believe His Word, the least we can do is to be on our guard; and if God has predicted scoffers, we ought to be prepared to meet them. This is the application which the apostle Peter makes of his own prophecy, and the passage is a remarkable instance of the application of a prophecy by the prophet who was employed to give it. Turn, then, to verse 17 of the chapter, and there you find him saying, “Ye therefore, beloved, seeing ye know these things before” (_i.e._, that you are fully warned beforehand), “beware lest ye also, being led away with the error of the wicked, fall from your own stedfastness.” He points to a danger against which we should watch, and a standard at which we are to aim. The danger is that, “being led away with the error of the wicked,” we should “fall from our own stedfastness.” The standard is, that we “grow in grace and in the knowledge of our Lord and Saviour Jesus Christ.” But if we are to act on this advice, it is clear that we must be armed in _the understanding_. It is not enough that we feel emotion; but we want to be able to give a reason for the hope that is in us—to know what that hope is, and to know also the strong foundation on which it rests. Most especially would I urge this on our young men. As you go through life you are almost certain to meet with scoffers, and when you do you do not want to be like them, willingly ignorant. Our position is perfectly impregnable! We have a rock under our feet which nothing can shake. We have facts which cannot be disproved, and an accumulation of evidence which is not to be found respecting any other book in the world. But we must not let our weapons remain locked up like old armour in some baronial hall, but we must have them out, and use them with vigour. They are made of the best of steel; but we must take care that there is no rust on the blade, and so be able to meet the scoffer; not by scoffing, but by the sword of the Spirit, remembering well the assurance of Scripture, that “the weapons of our warfare are not carnal, but mighty through God to the pulling down of strongholds.”