Dominion of sin

"For sin shall not have dominion over you, for you are not under law but under grace." Romans 6.14

Behind sin there is always a spirit. In fact, sin is an evil spirit. Tho who live in faith in the Lord Jesus are not hostage to the spirit of sin. But those who live a farce of faith, then yes, they become slaves to sin. They are the ones who usually say: I can not overcome my desires, my flesh, my sins ...