Here’s a good article about the soul and what death means: http://www.ucg.org/the-good-news/what-does-the-bible-say-about-the-immortal-soul .
A quote from that article:
The Old Testament describes the dead as going to sheol, translated into English as “hell,” “pit” or “grave.” Ecclesiastes 9:5-6 describes sheol as a place of unconsciousness: “For the living know that they will die; but the dead know nothing, and they have no more reward, for the memory of them is forgotten. Also their love, their hatred, and their envy have now perished …”
If the Old Testament describes death as an unconscious state, how does the New Testament describe it?
Many people are surprised to find that the term immortal soul appears nowhere in the Bible.
BUT WHAT ABOUT JESUS? What did he tell his disciples? Didn’t Jesus teach his followers about an immortal soul? As a matter of fact he didn’t. Have a look at this article: http://www.cgg.org/index.cfm/fuseaction/Library.sr/CT/BQA/k/99/Does-Jesus-Refer-an-Immortal-Soul-Matthew-1028.htm .
A quote from that article: Jesus once said to his disciples: “Our friend Lazarus has fallen asleep (kekoimetai — the perfect, passive of koimao); but I go that I may awake him out of sleep” (Jn. 11:11). In view of the subsequent context, the “awakening” clearly refers to the resurrection of Lazarus’ body (vv. 43-44).
No doubt that Lazarus’ body was asleep. But what about Lazarus’ soul? Was also his soul asleep? For example Martin Luther is among those who taught that both body and soul are asleep when we are dead. He once wrote, in one of his books, that the condition between death and the resurrection is like “a deep and dreamless sleep without consciousness and feeling”. But other theologians assert that only the body is asleep, the soul remaining awake, i.e. conscious .
On the other hand, a conscious soul is not necessarily the same as an immortal soul. It seems to be up to God to decide whether the soul can survive or must perish. We must not forget (see above) that in the Old Testament death seems to mean that also the soul is asleep (= unconscious)