The English word rapture is defined as meaning "snatched up" or "caught up." It comes from the same Latin root as "raptor," the kind of birds such as eagles who "snatch up" their prey. Although the word is not used in the King James Version Bible, or any common modern English translation, people derive their hope of it from only two Bible verses from the Apostle Paul:
"For the Lord Himself will descend from heaven with a shout, with the voice of an archangel, and with the trumpet of God. And the dead in Christ will rise first. Then we who are alive and remain shall be caught up together with them in the clouds to meet the Lord in the air. And thus we shall always be with the Lord." (1Thessalonians 4:16-17, NKJV throughout)
This "catching up" is called by many Bible teachers "the Rapture of the Church." Some teach that this will occur only at the Return of Christ to set up a Millennial Kingdom. But some who teach the doctrine are also convinced He will come SECRETLY to snatch away all true believers (which, of course, includes them!) and take them to heaven, to wait there while the rest of mankind suffers through the Great Tribulation. Many teach they will then return with Him when He comes to put an end to the Battle of Armageddon, and reign with Him on Earth during the Millennium.
Jesus told his disciples, in regard to the exact time of his return to earth and the establishment of his kingdom:
"But of that day and hour NO ONE knows, not even the angels of heaven, but My Father only." (Matthew 24:36)
Jesus restated his answer as to WHEN his kingdom
would be set up when, just before he ascended to heaven . . .
"Therefore, when they (the disciples) had come together, they asked Him, saying, 'Lord, will You at this time restore the kingdom to Israel?' And He said to them, 'IT IS NOT FOR YOU TO KNOW TIMES OR SEASONS WHICH THE FATHER HAS PUT IN HIS OWN AUTHORITY . . .'
"Now when He had spoken these things, while they watched, He was taken up, and a cloud received Him out of their sight." (Acts 1:6-7, 9)
In spite of these direct statements from Jesus, there have been those throughout history who have dogmatically predicted the day of the rapture and/or the day of Jesus' return to earth. Religious leaders foolish enough to "set dates" have been embarrassed and discredited when their predicted date quietly comes and goes.
A notable example of "setting dates" is William Miller, a Baptist preacher who predicted Christ would return sometime between March 21, 1843 and March 21, 1844. When March 21, 1844 came and went without incident, Miller adopted the new date of April 18, 1844 for Christ's return. When THAT date failed, one of Miler's associates recalculated the date of the Second Coming to be October 22, 1844. What is labeled "The Great Disappointment" occurred on that October day when Jesus didn't arrive as scheduled. Some soon abandoned faith in God entirely because of the false prophetic predictions. Still others continued their faith and became the foundation of the Adventist movement.
The lesson of history is that believers TODAY need to be VERY wary of any teacher or preacher who says he or she knows the date of Jesus' second coming.