Good changes for those who are saved and extremely trying and terrible changes for those who decided to be left behind and not accept Jesus’ free offer of salvation.
Behold! I tell 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 trumpet. For the trumpet will sound, and the dead will be raised imperishable, and we shall be changed. For this perishable body must put on the imperishable, and this mortal body must put on immortality. ~ 1 Corinthians 15:51-53