1 Corinthians 15:50-52

Now I say this, believers, that flesh and blood cannot inherit nor be part of the kingdom of God; nor does the perishable (mortal) inherit the imperishable (immortal). Listen very carefully, I tell you a mystery [a secret truth decreed by God and previously hidden, but now revealed]; we will not all sleep [in death], but we will all be [completely] changed [wondrously transformed], in a moment, in the twinkling of an eye, at [the sound of] the last trumpet call. For a trumpet will sound, and the dead [who believed in Christ] will be raised imperishable, and we will be [completely] changed [wondrously transformed].