Even when Jesus was on earth, His disciples already asked the question: ″When will the world come to an end?″ (see Matthew 24:3; Acts 1:6-7). Through the centuries, as early as AD 500, Christians have tried to predict the date of Jesus' return. Most of these predicted dates have passed.

While we may try to interpret specific world events as signs that Jesus' return is near, Jesus himself makes it clear that no-one knows which day or hour it will happen-″not even the angels in heaven, nor the Son, but only the Father″ (Mark 13:32). Only the Father has the authority to set such dates and times, and these are not for us to know (see Acts 1:7).

In 1 Thessalonians 5:2, Paul refutes the claims of false teachers who were speculating about the time of Jesus' return. He reminds the believers that ″the Lord will come like a thief in the night″. Paul is not saying that Jesus will return in the nighttime; rather, he is saying that Jesus will return unexpectedly and swiftly, since no thief would warn his would-be victims about his upcoming heist (see Luke 12:39; 2 Peter 3:10; Revelation 3:3). We are always to be alert, because the day could come any time. Jesus warns us: ″Keep watch, because you do not know on what day your Lord will come . . . the Son of Man will come at an hour when you do not expect him″ (Matthew 24:42-44).

Unlike some pastors and teachers today, Paul did not see eschatology, or the study of end times, as an advanced doctrine reserved only for more mature Christians and theological elites. Rather, he taught everyone, even spiritual babes, ″all the wisdom God has given us″, in order to present everyone fully mature in Christ (Colossians 1:28, NLT). Thus, in the few short months of his ministry to the Thessalonian church, Paul had already taught his flock about Jesus' return and the ″day of the Lord″-the time when God would come to punish the wicked and vindicate the righteous at the second coming of Christ (see Acts 17:1-4; 2 Thessalonians 2:5).

Christ's return is why Paul warns believers not to be worldly, indulgent, or spiritually complacent. We cannot fill our lives with the world's pleasures and let ourselves be lulled into a false sense of security. Since Jesus is coming again, it cannot be business as usual for Christ-followers. We must live in anticipation of Jesus' return, ever vigilant, ever expectant, and ever ready to receive Him. The day of the Lord is imminent!