In 1 Thess. 4:13-18, Paul speaks about how it will be when Christ returns. "We don't want you to be uninformed about those who have slept in the Lord."That refers to those who have died in Christ. Jesus died and rose again; and those who have died in Christ will also rise again. When Jesus returns, we who are alive will not be taken up ahead of those who died in Christ before us. They will arise from the graves. That will be the first resurrection. And we will be taken up together with them to meet the Lord. Unbelievers will not rise for another one thousand years. They will rise in the second resurrection.
At His return, our Lord will descend with a shout, with the voice of the archangel and with the trumpet of God. Then all the saints will be caught up to meet the Lord in the clouds. Jesus spoke about these very same matters, when He spoke to His disciples about His return. He said, "Don't believe those who say, 'He is here' or 'He is there' or 'He has come secretly' " (Matthew 24:26). What He was saying was that He would not come secretly, as many believe today. When He comes, it will be like the lightning that flashes from the east to the west. Every eye will be able to see Him.
When will Christ's coming take place? Jesus answered that too: "Immediately after the tribulation" (Matthew 24:29,30). Many believe that Christ will rapture His saints before the tribulation. But there is not a single verse anywhere in Scripture that teaches that. That is a doctrine of men. Jesus Himself clearly stated that His coming would be after the tribulation. The events mentioned here in1 Thess. 4:16, 17 are exactly the same as mentioned by Jesus in Matthew 24:30, 31: Jesus appearing in the clouds with the angels and a trumpet-sound, and the saints being taken up to meet Him.
In 1 Thess. 5:2, we read, "The day of the Lord will come like a thief in the night." A thief does not announce his coming, but comes unexpectedly. Thus, every unbeliever will be surprised when the Lord returns. We, the sons of light, however, are expecting our Lord to come (1 Thess. 5:4). We do not live in darkness. So we should not be asleep spiritually, but alert (1 Thess. 5:6).
How can we know whether we are awake or asleep? When a man is asleep, the things that are real around him in the room are invisible; but the things that are unreal (in his dreams) appear to be real. In the same way, a believer is spiritually asleep when the real things of eternity appear unreal to him, and the unreal things of this world appear real to him. This whole world is like an unreal dream when compared to heaven and eternity. The truly eternal things are the things of heaven. For believers who are asleep, the Lord will certainly come as a thief in the night. Paul says we look forward to that day and we eagerly await His coming.
People around us will be imagining that everything is peaceful and safe (1 Thess. 5:3). But destruction will come upon them suddenly, it says here "like birth pangs upon a woman with child" (1 Thess. 5:3). Jesus used the same expression when speaking of the last days in Matthew 24:8. Every woman knows that before she gives birth to a child there is a painful time of labour which can last for many hours. (Some mothers say that it was so painful that they felt like dying). It is only after that the child is born. This is a picture of the painful period of tribulation that will precede the coming of Christ. No child is born without those birth-pangs. And the coming of the Lord is not going to take place before this painful tribulation. We are not afraid of that period. It will be a great honour for us if the Lord allows us to be here as witnesses for Him and to lay down our lives for the sake of the gospel.