1 Corinthians 15:51-53

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]. For this perishable [part of us] must put on the imperishable [nature], and this mortal [part of us that is capable of dying] must put on immortality [which is freedom from death].