They are in/on Earth when they do that.
So, how long a break from the grave do they get and what do they do for a living until they go back in the grave?
BTW, isn't it more a question of being Ressurected into a situation with a New Heaven and New Earth? Then the Judgment. Then all the good guys abide with Jesus for eternity?
BTW, concerning the “New Heaven and New Earth” doctrine, did you notice that the planet Saturn seems to have a “reset button”? Check: http://cybercide.us/images/saturn_hexagon.jpg