The "rapture," meaning to catch up or catch away, may take place any moment. It will occur in an unexpected moment, so far as the world is concerned.
Imminence of the Rapture
The rapture of the prophet Elijah was preceded by a mysterious solemnity betokening some event to happen quite outside the natural course of things. So it will be when the Lord calls His own home. Instantly, the sleeping (dead) saints, both of Old and New Testament periods, awakened by the "shout," will be raised to participate in the "first resurrection." This will be selective and premillennial the resurrection "from among the dead." This is the more literal meaning of Phil. 3:11 and Mark 9:10 (JND), and many dike passages.
The "Out-resurrection”
The Greek phrase is ek nekron, out from (among) the dead. It is a distinctive expression and intimates the projection of divine power into the realm of death. But to be even more explicit, Paul, in Phil. 3:11, actually coins a new and unique Greek word, ex-anastasi, to express the resurrection of some from among others. The word translated shout, (keleusma), expresses that a certain relationship exists between the commander who gives the shout and the commanded who awaken.
The World Will not See the Rupture
What can this mean but that the world will not see this heavenly phenomenon, not being in any way related to the "Lord Himself." who gives the shout? The words of our Lord in John 5:29 indicate two distinct classes of resurrection, the "resurrection of life" (anastasis zoes), also called the first resurrection (Rev. 20:5), and the "resurrection of damnation," or judgment (kriseos).