Although the faithful hear that their joy is not in this world, something renders them careless and slothful: the false thought that they should live long. So, they don't direct their thoughts to the kingdom of God. This is why the Apostle, seeking to wake them up them from the drowsiness of the flesh, reminds them that the end of all things was near; by this he says that we should not sit still in the world, which we will soon leave. He does not, at the same time, speak only of the end of individuals, but of the universal renovation of the world; as though he had said, “Christ will shortly come, who will put an end to all things.
It is, then, no wonder that the cares of this world overwhelm us, and make us drowsy, if the view of present things dazzles our eyes. For almost all of us promise an eternity to ourselves in this world. Or, at least, the end never comes to our mind. But, if the trumpet of Christ were to sound in our ears, it would powerfully wake us up and not allow us to lie lethargic.
But it may be objected and said, that a long series of ages has passed away since Peter wrote this, and yet that the end is not come. My reply to this is, that the time seems long to us, because we measure its length by the spaces of this fleeting life; but if we could understand the perpetuity of future life, many ages would appear to us like a moment, as Peter will also tell us in his second epistle. Besides, we must remember this principle, that from the time when Christ once appeared, there is nothing left for the faithful, but with suspended minds ever to look forward to his second coming.