what happens after death ?

Ever thought about this? Crosses my mind every once in awhile. And I sit there and think about it until I just about shit my pants. Fear of the unknown is in my belief one of the biggest and most common fears out there. Only in this case, there is seriously no way to find out EVER. Do we believe those who have had "near death" experiences? Many accounts share similarities of seeing a bright light -- though I'm pretty sure that have been studies that say that your brain neurologically makes you think you see this. What happens to those who have no religion to believe in, whether by their own choice or not? If we all believe in one god, is Allah, God, Jesus, Yahweh, all the same entity?