A coffin in a dream rarely predicts death literally -- it more often marks an ending you're processing, or feelings you've buried rather than let yourself fully grieve. An open coffin can point to something from the past resurfacing, while a sealed one often reflects a chapter you've genuinely closed.
Destiny is not a matter of chance, it is a matter of choice; it is not a thing to be waited for, it is a thing to be achieved. (Bryan, William Jennings, 1860-1925, American Lawyer Politician)