To put it simply, the spirit is for the living, and the soul for the dead. We  can be witty or simple-minded or just witty, but the day we die, all  that beautiful spirit that we loved so much disappears with the body  envelope, as say those who have religion. It  seems that some spirits return to earth to pull the feet of the living  and walk with a sheet on the head, personally I have never seen. The  soul on the other hand would be especially useful after the death,  although some sells it during their lifetime (Faust, Swann, Robert  Johnson, etc ...). Most  religions believe that humans have a soul that continues after physical  death to go to hell or paradise, or to the land of ancestors, or come  back through reincarnation, or part of an "all "cosmic. The mind allows us to be aware of our mortality, and the soul would be the means to escape it. This is in any case the business of many organized religions.