Depending on which polls you consult, more than half of Americans and up to 67% believe that a person's soul goes to heaven or hell after death. This belief seems unusually strong considering that more and more Americans no longer identify with a fixed religion. "I'm not religious, but I’m spiritual" has become a common sentiment, and yet the idea of the soul continues to hold its place. One might even say it outstrips God as a matter of belief.
Look at how deeply embedded the word "soul" is in our culture, from soul music to soul searching. Once a word takes old, so does the concept it represents. To a pure rationalist, there's no reason to say that the gospels sung in African American churches are more soulful than a Beethoven symphony. When someone searches his soul, the psychological reality is that he is usually just consulting his conscience or weighing issues of right and wrong that came from childhood upbringing.