At the end of chapter 4, Paul gave a clear teaching about Christ’s second coming and urged, “Therefore encourage one another with these words” (4:18). In chapter 5, Paul addressed concerns about the timing of Christ’s return, concluding with a similar charge: “Therefore encourage one another and build one another up, just as you are doing” (5:11).

According to Paul, the Christian strategy for enduring in faith through trials is to strengthen one another with biblical truth. This is Christian teamwork in the church and home. How is the Christian family to endure against cultural attacks? By the husband’s encouraging his wife and the parents’ encouraging their children with biblical truths. How are Christians to minister to those faltering or discouraged? With the encouragement of biblical truth. We are to take the team approach in the Christian life, not tearing each other down but building each other up with the truths of God’s Word.

The truth that Paul wants to impress on the minds of his Thessalonian readers concerns their relationship with Christ. The way to be prepared for Jesus’ coming, he says, is to have our heads clear about what it means to be joined to Christ in salvation. Paul writes: “But you are not in darkness, brothers, for that day to surprise you like a thief. For you are all children of light, children of the day. We are not of the night or of the darkness” (vv. 4-5).

To describe the Christian’s situation, Paul employs the familiar biblical image of light. Believing in Jesus, the Christian no longer lives in the darkness but belongs to the realm of the light of Christ. Paul’s point is that Christians should not be unprepared for Christ’s coming, since we now belong to the light. By calling us “children of light,” he means that the blessings of God’s light have come to distinguish us and characterize our lives. Christians have gained knowledge of truth, have been warmed to God’s ways, have received spiritual life, and are guided by the light of God’s Word. Therefore, the day of the Lord should never come upon us as a “surprise,” like “a thief” (v. 4), since we have been looking forward to and preparing for that bright day.

Verses 4 and 5 present one of the Bible’s main principles for Christian living and sanctification, namely, that Christian living arises out of Christian thinking. We have seen earlier that Christians are persevere in faith by encouraging one another in biblical truth. Paul now explains how this works: God’s Word is taught to us, we begin thinking in light of God’s Word, and by God’s grace this new thinking yields a new and godly lifestyle. Jesus mandated this process of transformation by illumination when He prayed to the Father, “Sanctify them in truth; your word is truth” (John 17:17).

Having expressed his principle of reckoning who and what are we in Christ – children of light – Paul makes the application in terms of how we should therefore live in anticipation of Christ’s return. He focuses on three aspects of Christian readiness that will enable us to persevere in faith until the coming of Jesus to save us.

Paul’s first application is that since believers no longer belong to the darkness but are children of light, we should stay awake and not slumber: “So then let us not sleep, as others do, but let us keep awake” (v. 6). Being children of light, Christians should not engage in the nighttime activities of darkness. Those in the dark are asleep to God, unaware of what is happening in the world, and unresponsive to the call of the gospel. The children of light, in contrast, are to be awake to God’s plan and alive to God’s calling. Jesus warned, “Watch and pray that you may not enter into temptation” (Matt. 26:41).

A second biblical example of a sleeping believer was Samson, who lost his strength as his hair was cut in the night. Samson took his rest and made his peace with the world around him, settling into the arms of a Philistine named Delilah, who betrayed him. Samson’s slumber cannot be blamed of Delilah, however: Samson put himself to sleep spiritually by violating his covenant with the Lord. Once asleep, he awoke to his danger too late, realizing only then what he had lost through his alliance with the world. How many Christians today are asleep to the influences of popular culture, as that like Samson we become prisoners of worldly thinking and acting and so lose our usefulness to the cause of Christ?

A third example was given by Jesus in His parable of the tares and the wheat. A man sowed good seed in his field, “but while his men were sleeping, his enemy came and sowed weeds among the wheat and went away” (Matt.13:24-25). Likewise, in the tolerant spirit that grips the church today, there is little doctrinal vigilance over our churches and ministries. Christians are asleep to the threat of an active enemy who seeks to undermine and infiltrate the work of Christ’s kingdom so that we squander the gains given to us by God and lack the spiritual power to prevail in dangerous times.

In addition to staying awake, Christians maintain their readiness for Christ’s return by staying sober: “For those who sleep, sleep at night, and those who get drunk, are drunk at night. But since we belong to the day, let us be sober” (vv. 7-8). This application is a companion to the previous one: since Christians belong to the day, they should not be characterized by practices that take place during the night. Among these nighttime practices is a lifestyle that is inebriated with earthly pleasures and sin.

We should understand Paul’s call to sober living to involve more than drunkenness on alcohol or drugs. Today, this calling extends to the whole realm of entertainments of which Christians may imbibe, including movies and music that promote a sensual, self-absorbed lifestyle and glorify values that are contrary to God’s Word. In the workplace, Christians can become drunk with academic prestige, political power, or financial success. Paul’s emphasis on sober living, repeated twice in these verses, could indicate that this was a problem among the Thessalonian new believers. Given our similarly intoxicated culture today, many young believers and new converts will likewise need to seek God’s power to start living a sober life that no longer indulges in the kinds of worldly recreations that deaden us to the things of God.

Paul’s first two applications were negative in principle: “Let us not sleep…[or] get drunk” (vv. 6-7). The third application is active and positive, calling for Christians to arm themselves with biblical virtues: “having put on the breastplate of faith and love, and for a helmet the hope of salvation” (v. 8). Paul presents here for the first time in his writings an analogy that he will continue to develop in his later epistles, especially in Ephesians 6. He imagines Christians as preparing themselves for life in the same way that a soldier puts on his armor before heading into battle. It is not enough for Christians merely to say No to sin and worldliness; we must also actively cultivate faith, love, and hope in order to be guarded from threats that would endanger our salvation.

The two pieces of armor that Paul cites here are those that protect the vital areas of the heart and the head. The soldier’s chest was protected in battle by a breastplate, and Paul urges Christians to “put on the breastplate of faith and love” (v. 8). In Ephesians 6:14, Paul speaks of putting on “the breastplate of righteousness.” These descriptions go together – “faith and love” on the one hand and “righteousness” on the other – because faith and love are the means by which righteousness is received and then practiced. We are forgiven our sins and justified before God through faith in Jesus Christ (Gal. 2:16). Having believed, we then pursue a practical righteousness by leading a life of love – love for God and love for one another as outlined in God’s holy law.

Added to the breastplate that guards the vital organs is the helmet that protects the head: “and for a helmet the hope of salvation” (v. 8). According to Paul, the Christian who possesses a biblical hope for salvation is able to think clearly and resist blows that would daze him or her into unbelief or folly. We ground our hope in God’s sovereignty over history – a history that is defined by Christ’s saving death for our sins and that will conclude in Christ’s saving return.

The helmet of salvation will deliver us not only from worldly threats but also from a misguided dread of Christ’s second coming, as many Christians have sadly been led to do. For Paul and the early believers, Christ’s return was the hope for which they fervently longed. We are to live in readiness for that day, not suspending our lives and gazing at the sky in trepidation, but awake, sober, and armed with faith, love, and Christian hope.

If we trust in the work that Christ has done for our salvation, dying on the cross for our sins; if we cultivate a love for God and for one another according to God’s Word; and if we look in hope for Christ’s coming to bring us with Him into glory, we will be guarded for salvation and crowned with grace to stand without fear before a dark and wicked world that can be awakened to the gospel only by the witness that we are emboldened to give.

Paul makes it clear that Christians should expect struggle and difficulty as we await the return of our Lord. Some may wonder whether it is worth all the effort of staying awake, keeping sober, and arming ourselves with faith, love, and hope. Can we expect to prevail? Jesus answers, “In the world you will have tribulation. But take heart; I have overcome the world” (John 16:33). Paul urges believers to remind each other of such truths: “Therefore encourage one another with these words” (1 Thess. 4:18).

1 Thessalonians 5:4-8 Study Questions:

In verses 1-11, what are all the pictures or images that Paul uses to try to explain the relationship between believers and the world and the coming of the Lord?

How does Paul contrast the people of the day and the people of the night?

Paul’s point about staying awake belongs not so much with the danger of burglars but with the all-important difference between the old world (of darkness, sin and death) and the new world (of light, life and hope). What aspects of living as children of light or children of the day are challenging?