It is my understanding that when you die, your spirit leaves your body and is sort of...like, given a judgement for heaven or hell. Then, your spirit resides in heaven or hell until the end of time/ end of the world/ second coming. At this point, the spirits of the dead are reunited with their bodies (however the heck that works, don't ask me...). These who have died and are reunited with their bodies and those who had not yet died all are then subject to a more general judgement. This isn't being judged twice, those who died still remain in heaven/hell depending how they were judged upon their death, but those who are alive at the second coming are judged for heaven or hell here. At this time, all creation has a chance to understand God's divine justice and his reasoning as to why everyone is being sent to heaven or hell so that all might know God's awesome power, and we'll then see why he has created, he divine plan, and his ultimate Glory over evil in ways that we can't comprehend in this life. Reunited with a body, people spend eternity in either heaven or hell.
We were created to be in bodies before the fall, so it seems reasonable that we would spend eternity in a body. Jesus rose from the dead in a body so that leads me to think the body is pretty important as part of our human being...both here in this life and the afterlife.
I guess we'll all definately find out in the end!