(1 Corinthians 15:51) Listen, I tell you a mystery: We will not all sleep, but we will all be changed— in an instant, in the twinkling of an eye, at the last trumpet.
For the trumpet will sound, the dead will be raised imperishable, and we will be changed.
For the perishable must be clothed with the imperishable, and the mortal with immortality.
Rapture believers believe Jesus will rescue those worthy of escaping the tribulation. Non-believers on the earth at the time will be left behind for the tribulation period.
The tribulation period will last for seven years, the final seven years of this age, until Christ returns to set up his earthly kingdom during the Millennium.