The idea that, at the time of Christ’s return, all faithful Christians will be taken away at once is widely believed by Christians. It has been termed “the rapture,” although that word never occurs in the Bible. An essential component of this belief is that there is a 7-year period of great trouble upon the earth, commonly called the “tribulation,” a word that is found in the Bible. The Bible, indeed, says there will be a time of great trouble around the time of Christ’s return: "For then there will be a great tribulation, such as has not occurred since the beginning of the world until now, nor ever will.” (Matt. 24. 21) However, there is no scriptural evidence which proves it is a 7-year period.
Most people who believe in the “rapture” believe it has two parts and is called “pre-tribulation rapture”—(1) “the secret rapture” of Christ’s followers which precedes the period of tribulation, and (2) then His return visibly with his saints to dispense his wrath on the world’s nations. Another view of the rapture (also pre-tribulation) is that the true believers will be taken from the earth by God into heaven, and be transformed into their spiritual bodies while the non-believers remain on the earth to suffer severe tribulation. The post-tribulation theory says that believers will be protected during the tribulation and gathered to heaven at its conclusion.
The concept of the “rapture” is based on 1 Thessalonians 4:16-17: “For the Lord Himself will descend from heaven with a shout, with the voice of the archangel and with the trumpet of God, and the dead in Christ will rise first. Then we who are alive and remain will be caught up together with them in the clouds to meet the Lord in the air, and so we shall always be with the Lord.” The Greek word translated “caught up” means “to seize.” In the Latin Vulgate translation, the word “rapiemur” was used, meaning “we shall be snatched, we shall be grabbed, we shall be carried off.” From the same root of this word, we have a name for a class of birds which swoop down and snatch up their prey—raptors. From this, “rapture” was used in English to refer to this gathering of the last members of the disciples of Jesus.
So, does the Bible say the gathering of believers is before or after the severe trouble which will mark the end of this age and the return of Christ? The answer is: both. Christ returns before the trouble to gather his bride. That is what the 1 Thess. 4:17 passage is describing. The promise to the “overcomers” in the message to the church of Laodicea (the last period of church history before these end-time events) is, “He who overcomes, I will grant to him to sit down with Me on My throne, as I also overcame and sat down with My Father on His throne.” (Rev. 3:21) Matt. 19:28-29 says: “Jesus said to them, ‘Truly, I say to you, in the new world, when the Son of man shall sit on his glorious throne, you who have followed me will also sit on twelve thrones, judging the twelve tribes of Israel. And every one who has left houses or brother or sisters or father or mother or children or lands, for my name’s sake, will receive a hundredfold, and inherit eternal life.’ “But then there is another group of believers whose position in heaven is not ON the throne, but rather BEFORE the throne. Rev. 7:9-17 says that this “great multitude” “came out of [or through] the great tribulation”: “After this I looked and behold, a great multitude which no man could number, from every nation, from all tribes, and peoples, and tongues, standing before the throne and before the Lamb, clothed in white robes. . . v. 13 Then one of the elders addressed me saying, ‘Who are these, clothed in white robes, and when have they come?’ I said to him, ‘Sir, you know.’ And he said to me, ‘These are they who have come out of the great tribulation; they have washed their robes and made them white in the blood of the Lamb.” So these believers were gathered during or after the tribulation.