the human being
Your brain is the collection of nerve cells in your head. Your soul is your mind, your will and your emotions. What separates man from the animals, most people believe, is that man, being formed in the image of God, also has a spirit.
The physical brain is a mass of nerves and (by itself) little better than a computer. I think you can intuitively discern that there is a difference between your “mind” and your brain.
The spirit and the soul
In Genesis, God breathed the breath of life (Hebrew neshama – spirit) in the chemical compounds of the soil, and Adam became a living soul. (Genesis 2:7)
The New Testament book of Hebrews (4:12) speaks of dividing the soul and spirit. The Bible clearly differentiates between the two. So what are they?
The soul
The mind is essentially your soul. The soul is your mind, will and emotions. Your “I” (Joyce Meyer likes to say: “I want, I think, I feel”) Those are the faculties of your soul.
The spirit
Few people are aware of the faculties of the spirit (which are awareness and communication with God) because they are born spiritually dead.
Your spirit was essentially dead as far as God was concerned until you accepted Christ and were baptized. Then God “quickened” your spirit. (Ezekiel 36:26 also John 3:5)
The faculties of the human spirit are communication with God, conscience and intuition. About the only communication with God that unbelievers have experience with is a nagging conscience, or when God is trying to call them. That’s all. As a mature believer, his intuition will be sharpened. Some people, like the late Watchman Nee, would not budge until he heard from the Holy Spirit. Others of us, God has to use a baseball bat to get our attention. (figuratively, of course)
In summary
The term “immortal soul” is really a misnomer. Technically, the spirit is the immortal part of you. The soul will resurrect. Some souls will rise to life, and others to judgment.
Let God soften your conscience, let Him remove the layers of callousness that harden every time you ignore your conscience, and let God speak to your spirit. You’ll be glad you did!
additional study
For a very detailed look at the body, mind, and spirit, get Watchman Nee’s book, The spiritual man. However, be careful. There is a lot of stuff. And it is very deep.