"Behold, I shew you a mystery; We shall not all sleep, but we shall all be changed, In a moment, in the twinkling of an eye, at the last trump: for the trumpet shall sound, and the dead shall be raised incorruptible, and we shall be changed." (1 Corinthians 15:51-52)
This is one of the greatest promises in the Bible, assuring us that "we" (i.e., all believers, whether dead or living when Christ returns) shall suddenly be changed, with our dead or dying bodies instantly transformed into incorruptible, immortal bodies, which can never die again.
This great change, when it finally occurs, will take place "in a moment." The Greek here is en atomo, "in an atom of time." This word, implying the smallest entity conceivable by the Greeks, is used only this one time in the New Testament. It is further described by "the twinkling of an eye," where "twinkling" is the Greek rhipe, also used only this once. Evidently there is nothing else in this present world comparable in rapidity to this miraculous change which will be called forth when "the Lord himself shall descend from heaven with a shout, with the voice of the archangel, and with the trump of God" (1 Thessalonians 4:16).
The great shout (probably uttered by Christ Himself as at the tomb of Lazarus) will instantly create new bodies for both dead and living believers. "The dead in Christ shall rise first: Then we which are alive" (1 Thessalonians 4:16-17).
Our new bodies will be like Christ's resurrection body. He "shall change our vile body, that it may be fashioned like unto his glorious body, according to the working whereby he is able even to subdue all things unto himself" (Philippians 3:21).
Christ is able thus to create new bodies for us in a moment, just as when He created all things in the beginning: "He spake, and it was done" (Psalm 33:9). HMM