The Spirit of the Lord is the answer to the soul's angst. He is the light that orders our emotions into strong and healthy places and our intellects with wisdom.
The division between soul and spirit is, in my understanding, that the soul is our personal state and spirit is what we take on in terms of direction, like a three masted schooner (soul) when the sails are filled by a prevailing wind (spirit).
Another metaphor: I can get into my car at night. I know how to drive it. It is in good working order. Turning the key, applying pressure to the gas pedal and steering are all available to me. I can engage the car in the darkness. I now must determine where the road is, where the turns are that achieve my destination, and I must avoid other vehicles along the way in addition to pursuing my goal. If I fail to turn on the headlights, my journey will be rough even dangerous. I will most likely get lost, if I manage to stay on the road and out of the way of others. This is me in my soul. Flip the switch to provide myself headlights, and the journey becomes successful.
Real life: A doctor's office and pharmacy mis-communicate. It is late afternoon and a prescription needed for a sick infant is unavailable for filling by closing time for the pharmacy. No other avenue of gaining the needed medicine is available. This means another night for the child at the vagaries of a painful condition that might have been easily remedied. Passing through this "street" of circumstances, do I drive darkly with my emotions filled with worry and my mind involved in preparing blistering complaint speeches for the doctor's office and pharmacy clerks by morning; or do I give myself to the work of caring for the child peacefully, giving praise to the Father for grace in the midst of this? Morning comes. Do I have angry speeches (the dark street) or pleasant and encouraging words (the lighted way) for the personnel I contact once business hours ensue?
Living by the spirit is living in a light that is not from within myself. The spirit which I experience is not really a part of my make-up within the soul. It is a spiritual functioning of the soul by an essence the Father has both designed and provided. Or so it seems to me in the Wild Wood.