How is my soul different from my spirit?

I once thought my soul and spirit were one and the same. I read the word "heart" and assumed it meant my soul, as in Matthew 12:35, "A good man out of the good treasure of the heart bringeth forth good things: and an evil man out of the evil treasure bringeth forth evil things."

Later I learned we are a tri-une being, created in the image of God, who is also a trinity: Father, Son, and Holy Spirit. So is our spirit part of our heart? 

I read that sin, iniquity, unbelief, etc., come from the heart but not the born-again spirit. 

One of my favorite ministers says: 

"Hebrews 4:12 suggests that spirit and soul are both part of the heart; hence, the scriptures admonish us to believe with all our heart (Acts 8:37), have singleness of heart (Col. 3:22), and tell us our hearts can have two minds or ways of thinking (Jas. 4:8).

"Even Christians still struggle with things like pride and foolishness which Jesus said came out of our heart. It's certain that our born again spirit is not the source of these sins. The heart encompasses more than our spirit.

"The English word "soul" comes from the Greek word "psuche," translated "heart, life, mind, and soul." The mind is the principle and leading part of the soul, followed by the will and emotions. We could also describe the soul as being the hidden part of all existing beings or what most people would call the personality. The soul is the center of the feelings and emotions, appetites and desires, as well as sense perception and consciousness. The soul may also speak of the totality of a person - his total being or self, a person, and the hidden man or inward man. 

"The soul and the body do not get born again. It is the spirit of man that becomes totally new at salvation. So, although every believer receives the same miraculous spiritual rebirth, the visible results of that inward change will vary from person to person according to how much he renews his mind. The term "heart" can include all of the inner man - spirit, soul, or any portion thereof."

The peace of God will keep your heart at rest in Christ Jesus, through any trial or storm. Pastor Shelia Hart Artt's story, "With a Knife at my Throat, I Saw the Lord" from my book SUPERVENTION is a marvelous example of this truth.