Lust is a desire to have our way regardless of God's truth or another person's will. It is making a person an object to be used and not a person to relate to and learn to love. This ought not to be and we will see, causes very serious consequences.
In the great eighth chapter of Romans, which is the solution to St. Paul's wrestling with his sin in chapter seven, we see a profound truth. It is that those who live according to the flesh and are controlled by its unholy desires, set their minds on and pursue those things which gratify the flesh. But those who are according to the Spirit and are controlled by the desires of the Spirit, set their minds on and seek those things which gratify the Holy Spirit. So the life of the Spirit requires a mind change.