Wow, did this thread get derailed fast. Hopefully, the Mods or someone else will direct the interlopers to start another thread, or move it.
Anyway, back the the ORIGINAL topic of this thread…
One of the things that has always made it hard to answer the question as posed by you is that the Bible tends to use the two terms – soul and spirit – somewhat interchangably. Thus a person that favors interpreting these words directly from the Bible has had to be pretty selective or he finds his definition conflicting with other parts of the Bible. This has also led to some strange interpretations as well.
Secondly, metaphysical concepts such as these have gone through a development within the Bible itself, from the OT to the NT, with our understanding becoming clearer. This is especially true when, within the NT itself, especially within John and Paul’s writings, Greek philosophical concepts are employed to help make these ideas clearer.