Romans 8:11

But if the Spirit of him that raised up Jesus from the dead dwell in you, he that raised up Christ from the dead shall also quicken your

mortal bodies by his Spirit that dwelleth in you.

We are often told to walk by the spirit and we shall not gratify the desires of the flesh, while these are pure words of knowledge they represent a man who only walks with God at one glory. However, man is called to be one with God and this entails a rapture of our mortal bodies so that we can bodily dwell in him as he does in us. The Rapture is not a window for the church to escape tribulation but a time when God quickens his sons to the fullness of life which is a key to entering the kingdom.