Romans 8:13

For if you are living according to the (impulses of the) flesh, you are going to die.  But if (you are living) by the (power of the Holy) Spirit you are habitually putting to death the sinful deed of the body, you will (really) live forever.

We are a spirit. We have a soul, and we live in a body.  When we learn this, we can clarify the order of leadership over our flesh (body) and soul (mind, will, and emotions).  The spirit is to rule over the flesh and the soul with the help of the Holy Spirit and the word of God.  Without this knowledge, people tend to follow their feelings and feelings change and the flesh rules.