The question is entertained often as to whether man is made of two parts (Body and Spirit/soul) or three parts (Body, Spirit, and Soul). While the answer may be truly far beyond our comprehension, I thought to outline my basic understanding of the makeup of man.
It seems that the soul is that thing within man that unites the spirit and the body. Jesus said, “the spirit indeed is willing, but the flesh (human nature) is weak.” It is though the body and soul together constitute the “flesh”, and the spirit and soul together constitute the “spiritual”.
Flesh can contain a spirit or spirits, and still not be a “spiritual being” in itself, as seen by the possession of pigs in mark 5. But with humans, it seems we are given our own individual spirit that is fused with our soul… virtually inseparable. Hebrews 4:12 seems to intimate that the spirit and soul of man are so tightly bound together that nothing but the power of the Word of God could, “pierce even to the dividing asunder of soul and spirit”.
Flesh can also have soul (life) and not have a spirit, as with animals. The same Hebrew word translated “soul” relating to man is also translated as “creature” relating to animals. Unlike trees and plants, animals have the capacity to interact and show affection… in effect, they are animated with life. A fundamental difference between humans and animals is that our souls were fused with our spirit, giving us the ability to commune with God on a spiritual plane, and have an everlasting existence.