Because I believe we each have an eternal human spirit attached to our being by God at the moment of conception.
The Bible provides word imagery of heaven and hell, etc, but this does not convey any real insight into our spiritual nature and the world beyond this world. So we read the Bible concerning life after death and it presents ideas and imaginings that are just that. They do not have any real substance because no words can describe the spiritual dimension.
As for believing in the Bibles Teachings, that's find, but remember those Teachings are interpreted by individuals and religious groups differently to each other, so the Bible is very subjective and not absolute. It's truths are all relative truths and not absolute.
