What is the difference between the mind and the soul?

I often hear the soul referred to as the part of us that leaves when we die, the part that goes to (and perceives) life after death, and the part of us that is us(instead of the body). My problem is that all of this seems to apply to what we think of as a mind.

If there is no difference, the idea of selling one's soul would simply mean allowing someone else to think for you and being soulless wouldn't mean evil so much as dumb. There seems to be some sort of different connotations to the statements. Would these differences come from something more associative?

 

In studying the New Testament, I have come across teachers that teach the idea that man is a three-part being. We are a spirt, we live in a body and we have a soul. The soul is also three-part, consisting of our mind, will, and emotions. If our soul is truly the mind, will, and emotions, wouldn't that be the most important part of us? We aren't simply our intellect alone. We are a total of what we think, feel and what we choose to do with our mind and emotions. I have to admit, I'm really just thinking out loud here. Interesting to ponder, though!