The Brick Walk
How do we understand the makeup of man? Scripture says that man is made in the image of God (Gen. 1:26) and that man also is one distinct peson consisting of three areas. Those we call - The Body - The Soul - The Spirit. Paul identifies these for us in his blessing at the end of 1 Thessalonians; "May the God of peace Himself sanctify you entirely; and may your spirit and soul and body be preserved without blame at the coming of our Lord Jesus Christ."
There has been debate about whether we have a body, and a soul/spirit (a two part nature) or if we have a three part nature. Hebrews 4:12 says that the word of God can pierce "as far as the division of soul and spirit", and I believe that even when separated there is a God designed unity of all three which will be ultimately realized in God's time and plan.
The body is the physical part of man. It is the bone, the flesh, the muscles, the organs, the brain; everything in the world we live in that will undergo decay. The physical part begins at conception and goes on until death. We believe in a resurrection of the physical body at some point where it will be restored and continue on with the soul and the spirit for eternity. When scripture refers to the desires of the flesh it is usually talking about bodily desires not reigned in by a soul in submission to God.
The spirit is the eternal part of man. Creation has a physical dimension and a spiritual dimension and I think just as there are laws of physics that govern the physical there are also laws of spiritual physics that govern the spiritual, perhaps even the same laws. The spiritual cannot be comprehended (or observed) by the physical but it is just as real. In fact, scripture says that certain things that God has made in the physical are based on patterns from the spiritual (check Hebrews re the Tabernacle for example). So we have a physical body as well as a corresponding spiritual body. I suspect that the spiritual body grows with the physical but does not age (or look old) after a certain point, and that babies that die have spiritual bodies that gradually grow to adulthood. That, of course, is just my opinion.
The soul is our personality. It is who we are as a person, and it includes our memories, desires, and decisions. It is actually the link between the body and the spirit of man. A lot of who we are comes from the chemical and electrical processes of the brain but we need to remember that a lot of the same things are going on in our spiritual brain and body. At death then, the soul and spirit leave the body and our personality and memories go on into eternity, where we wll one day be united with a glorified physical body. Scriptural references to the mind or heart of man are usually talking about the soul.
While walking down this path remember what Jesus said to Martha in Luke 11; I am the resurrection and the life; he who believes in Me shall live even if he dies."