Death can't be the end for people because people do seek for pleasure and closure.
To live on after a significant persons passing requires pleasure (comfort) and some level of appreciation for the significant persons contribution (respect).
Heaven contributes to significantly loved people and to conclude they are not suffering and onto better things.
Hell contributes to significantly hated people and to conclude they are to continue suffering and will not be doing better.
Unless pleasure (comfort) is brought to people who experience a significant persons death, closure will be sought in Heaven and Hell because it is one way to interpret a level of respect for the result - Death.