Why do people think their spirit goes immediately to heaven when they die?

Its because such religious teachings all share one basic idea and that is that some part of us survives the death of the physical body. And of course according to almost every religion, past and present, we somehow live on forever with the ability to see, hear, and think. Yet, how can that even be? You see, our senses, along with out thoughts, are all linked to the workings of our brain. And most importantly, at death, the brain stops working. Our memories,our feeling and senses do not continue to function independently in some mysterious way. They do not survive the destruction of our brain. Even The Bible share that thought, just read Ecclesiastes 9:5.