v. 4. But ye, brethren, are not in darkness that that day should overtake you as a thief.
v. 5. Ye are all the children of light and the children of the day; we are not of the night nor of darkness.
v. 6. Therefore let us not sleep, as do others, but let us watch and be sober.
v. 7. For they that sleep, sleep in the night; and they that be drunken are drunken in the night.
v. 8. But let us, who are of the day, be sober, putting on the breastplate of faith and love, and for an helmet the hope of salvation.
v. 9. For God hath not appointed us to wrath, but to obtain salvation by our Lord Jesus Christ,
v. 10. who died for us, that, whether we wake or sleep, we should live together with Him.
v. 11. Wherefore comfort yourselves together, and edify one another, even as also ye do.
The Day of Judgment will come suddenly to Christians and unbelievers alike; but the contrast which the apostle brings out is this, that only the latter will be surprised by it. Christians are watchful, open-eyed, alert; they do not know when the last day is to come, but they are wide awake to any signs of its coming. This fact is brought out by the apostle in describing the state of the Christians: But you, brethren, are not in darkness that the day should surprise you like a thief; for you all are children of light and children of the day; we are not of the night nor of darkness. The unbelievers, the scoffers, are in darkness; moral corruption and want of intellectual insight renders them unable to read the signs of the times. With this condition the believers have nothing in common; their spiritual and intellectual condition is not such as to give them a false security and to make them blind to the signs of the times. They cannot be surprised by the coming of the last day, as a person would be when sleeping soundly in the darkness. The apostle rather makes a broad and sweeping statement concerning all Christians, namely, that they are children of light and of the day. As converted saints the believers are partakers of the salvation in Christ; they are now a light in the Lord; they know Jesus, their Savior. And they have put on the armor of light; their reason, enlightened by the understanding of God's will, chooses those things which will bear the inspection of all men in the sight of God; they walk honestly, as in the day, Rom_13:12-13. With pointed emphasis the apostle makes the personal application: Not are we (Christians) of the night nor of the darkness. We have nothing in common with the unfruitful works of darkness; we refuse to have our minds influenced by the judgment of unbelievers in spiritual matters.
With this thought the apostle now connects his admonition: Now, then, let us not sleep, like the rest, but let us be vigilant and alertly sober. For the sleepers sleep by night, and the drunkards are drunken in the night; we, however, being of the day, let us be in our alert senses, having put on the breastplate of faith and love and as our helmet the hope of salvation. It will not do for Christians to yield to drowsiness, to fall into spiritual sleep, in these last days of the world, which is the condition of the rest, of the great majority of the people in the world, of all the unbelievers. The Christians' constant attitude is that of vigilance, of watchfulness, of alert soberness, 1Pe_5:8. For the sake of comparison the apostle refers to the example of the spiritual sleepers, of those that are of the night and the darkness. Their habitual condition is the very opposite of sober alertness: they are asleep in the night of sins, they are like people under the influence of strong drink, drowsy, stupefied, unable to understand the dangers of these latter days. The unbelievers, in their carelessness and profligacy, indulge in the lusts of the flesh, avoid all means of instruction, are unable to discern the signs of the times, preferring their ignorance to the light of God's Word in faith and life. We Christians, on the other hand, belong to the day, where the light of the Word of God rules. Therefore it behooves us at all times to make use of sober vigilance; for if the saying is true anywhere, it is true in spiritual matters, that eternal vigilance is the price of liberty. To that end we should put on the armor of God, which enables us to guard both body and soul against attacks from all sides. There is the breastplate of faith and love, of a faith which rests upon the merits of Christ and therefore manifests itself in a life of love; there is the helmet, namely, the hope of salvation, the certain trust and confidence that God, who has made us sure of the redemption in Christ Jesus, will confirm us in this faith to the end, finally taking us from this vale of tears to Himself in heaven, where we shall enjoy complete salvation and deliverance from sin and death, world without end. Eph_6:13-17.
This point the apostle now drives home with the comforting assurance: Because God did not appoint us to wrath, but for the acquisition of salvation through our Lord Jesus Christ. God did not ordain us, set us forth, for the purpose of enduring His wrath; for it is not His will that any man should perish; He brought no man into being only to elect him to everlasting perdition. Of this fact the believers are so sure that no consideration of human logic can shake their position in the matter. We Christians know that we have been appointed by God for the obtaining or acquisition of eternal salvation, not by our own works or merits, but through our Lord Jesus Christ. How this salvation was gained and its possession by us made possible, St. Paul writes: Who died for us, in our behalf. By giving Himself into death in our stead, for our benefit, Christ gained a complete redemption for us. But this fact puts us under the obligation: So that, whether we are awake or asleep, we should live together with Him. Under all circumstances and conditions we Christians belong to the Lord, being in the most intimate fellowship with Him, partaking of His life, whether we are carrying out the obligation of alert watchfulness in this life, or whether our body is peacefully sleeping in the grave. On the great day of His coming, therefore, we shall appear as living with him, no matter whether this coming finds us watching in life or sleeping in death. In any event, to be with Him will be the true life out of death. Well may the apostle therefore add: Wherefore encourage one another, and let each one edify the other, even as you also do. While Paul's fine courtesy and tact acknowledge the progress which has been made by the Thessalonian Christians in this respect, he does not hesitate for a moment to urge them forward toward further comfort and edification. Exuberant energy, joyful hopefulness, willing steadfastness must characterize the Christians at all times.