What’s Up With the Title?
Revelation never actually got a title. Maybe John thought titling his letter was a little bit pretentious.
Over the years, the book has been called by all different names (The Apocalypse, The Revelation of Saint John the Divine, Fire and Brimstone 'R' Us). But really, the first line, "The revelation of Jesus Christ…" is the closest thing you could find to an actual title.
Because that's a bit of a mouthful, people usually just shorten this to reflect the first word: apokalupsis. Though we usually think of an "apocalypse" as a bad thing (because it kind of is), it really just means an "uncovering" or "revelation." And that one word pretty much sums up the whole book. The story is about something that once was hidden (God's plan for humanity) and has now been uncovered or reveled. Voilà!