1 Corinthians 15:51-52

Take notice! I tell you a mystery (a secret truth, an event decreed by the hidden purpose or counsel of God). We shall not all fall asleep [in death], but we shall all be changed (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 [in Christ] will be raised imperishable (free and immune from decay), and we shall be changed (transformed).