It often seems that governments, nations, and other institutions are the enduring feature of human history, and people are transient elements. Christianity says that this is radically wrong. Note that there is a subtle difference between resurrection and the existence of an eternal soul. Many religions have held that human beings have an immaterial soul, which does not die when the body does. However the distinctive Christian doctrine is not the eternal nature of the soul, but the resurrection of the body.
Humans are unified beings.
The body is an essential part of the person. In heaven there will be some analog of the body. Judgement Christians believe that there will be a judgement. In this, everyone's life will be evaluated. Those who depend upon Christ for salvation can be assured that they will pass this judgement.