Muslims believe in resurrection. At death, the body waits in the grave (barzakh) and sees the events of its life. This can be quick or very slow and painful. On Judgement Day, people are sorted according to their beliefs and actions. The wicked are cast into hell; the truly good go straight to paradise. All others cross As Sirat bridge, carrying the book of their deeds (sins make it heavier). The bridge is sharp and so they are purified from sin before going to paradise.