I think we are aliens to this world. We came from another universe, according to Islam - Adam and Eve's journey from heavens. Also, According to all monotheist religions, our souls will leave this planet after we expire.
There's an Islamic lecture video on youtube that talks about hereafter and Islamic teaching. I couldn't watch it past 1st five minutes - too intense. If you have the guts to watch it, just go to youtube and search the term" hereafter islam" without the quotes and click on the guy in the white khamis.