Paul, when he used that word "departure [G359 - analysis ]" (2Tim4:6), he was referring to his death (per context).
However, "rapture [G726 - harpagēsometha ]" (1Thess4:17), when the entire corporate "Church WHICH IS HIS BODY" will be "SNATCHed-up/-away]" at once (in ONE "snatch-action"), that...