Horatius Bonar emphasizes the urgency of being prepared for Christ's swift and sudden return, as highlighted in Revelation 16:15. He warns that Christ will come unexpectedly, like a thief in the night, and urges believers to remain vigilant and keep their spiritual garments intact. Bonar outlines the importance of watching, maintaining communion with God, and being ready to meet the Lord, as neglecting these can lead to shame and exposure. He reassures that those who watch and keep their garments will be blessed, while also issuing a stark warning to the unprepared. The sermon serves as a call to awaken from spiritual slumber and be ready for the imminent return of Christ.

"Behold, I come like a thief! Blessed is he who stays awake and keeps his clothes with him, so that he may not go naked and be shamefully exposed."—Revelation 16:15. These are words specially for the last days. They suite all times, no doubt—for Christ is ever coming; the last trumpet is ever about to sound; the fire is ever ready to be kindled; the Judge is ever at the door! But they suit the last days best, and are meant for these. With eighteen hundred years behind us now, we may take them home most solemnly to ourselves— (1) They warn. (2) They quicken. (3) They rouse. (4) They comfort. I. The COMING. It is the long-promised advent. Christ comes! He comes— (1) as Avenger (2) as Judge (3) as King (4) as Bridegroom. The same Jesus who left the earth is about to return to it. 'Behold!' He says to a blind, heedless world. 'Behold!' He says to a cold and slumbering Church. 'I come!' He is herald to Himself. 'As a thief'—at midnight; when men are asleep; when darkness lies on earth; when men are least expecting Him; when they have lain down, saying, "Peace and safety.' 'Behold, I come like a thief!' Without warning, though with vengeance for the world in His hand—when all past warnings of judgment have been unheeded. Without further message—for all past messages have been vain. Like lightening—like a thief—like a snare. Like lightning to the world—but the Sun of morning to His Church. Like a thief to the world—but like a bridegroom to the Church. Like a snare to the world—but like the cloud of glory to His own. II. The WATCHING. Not believing, nor hoping, nor waiting merely; but watching—as men do for some special event—whether terrible or joyful, of which they know not the time. Waiting was the posture of the Jewish Church for the first advent; watching is ours for the second. Watch, said the Master. Watch, said the servants in primitive times. Watch, we say still, for you know neither the day nor the hour of His arrival. Watch, for that day is great and glorious. Watch, for you are naturally disposed to sit down and take your ease. Watch, for Satan tries to lull you asleep. Watch, for the world, with it riches, and vanities, and pleasures, is trying to throw you off your guard. Watch upon your knees. Watch with your Bibles before you. Watch with wide-open eye. Watch for Him whom not having seen, you love. III. The keeping of the GARMENTS. Be like Nehemiah, who, when watching against the Ammonites, did not put off his clothes night nor day. Keep your garments all about you, that when the Lord comes He may find you not naked, but robed and ready. Do not cast off your clothing either for sleep or for work. Do not let the world strip you of it. Keep it and hold it fast. It is heavenly clothing, and without it you cannot go in with your Lord when He comes. IV. The BLESSEDNESS. Blessed is the watcher; blessed is the keeper of his garments. Many are the blessed ones; here is one class specially for the last days. How much we lose by not watching and not keeping our garments! (1) Watching is blessed, for it cherishes our love. (2) Watching is blessed, for it is one of the ways of maintaining our communion. (3) Watching is blessed, for it is the posture through which He has appointed blessing to come, in His absence, to His waiting Church. V. The WARNING. Lest you walk naked, and men see your shame. 'Shame' has three meanings—(1) the shameful thing or object; (2) the feeling of shame produced by the consciousness of the shameful thing; and (3) the exposure to shame and scorn from others. The first of these is specially referred to here. But all the three are connected. Adam was ashamed at being found naked when the Lord came down to meet him; how much more of shame and terror shall be to unready souls at meeting with a returning Lord! It will be the beginning of shame and everlasting contempt. They shall be put to shame before men and angels; they shall be overwhelmed with confusion before the great white throne. The universe shall see their shame. O false disciple, come out of your delusion and hypocrisy, lest you be exposed in that day of revelation! O sinner, make yourself ready, for the day of vengeance is at hand!