I guess because atheists do not have a sense of a religious. You know religion is a bond a person with his god. should you (atheists) believe is that every life is a journey toward us into the next life. you believe about life after in the world?
It is impossible for an atheist to believe in life after death or rebirth because these ideas are opposed to humanist dogma and all atheists are humanists since what else could they be?. Since there is so much evidence of life after death, the burden of proof has shifted to the skeptics, they fail to offer a serious scientific explanation to justify humanism.
The sole purpose contradiction or argument these religious morons hold against atheism IS just philosophical at best. True that philosophy has it's place in our world but when philosophy turns into religious preaching it is then when humanity begins to lose the battle against these idiots.