I would say the soul would be more than the engine. The soul would be like the computer system that coordinates everything, from the smog device to the fuel injection system to the brakes.

I do emphasize that we cannot just get out of the Bible a definition of the soul.

Now, of course, you have guidance devices and all sorts of things. The soul would be more like the way this is all hooked together, a system of coordination.

We see that the soul is the deepest and the most vital part of the person as a whole. It is often treated as the person, and we actually do this when we talk about "saving our soul."

The spirit is the part that is supposed to consciously direct everything in the person, including the soul.