You do not break the cycles of sin in you life by repeating, “I will not do that”.  Saying it does not stop it; it only keeps the sin at the forefront of your mind.  The answer to sin must be more than, “Just say no!”  The only way we can expel sin from our lives is by loving God with our whole being and our neighbor as ourself.  The absence of this kind of love is a highway for all manner of sins to take root in our lives.  Until we love the good more, we can never rid ourselves of the evil.

“Above all, keep fervent in your love for one another, because love covers a multitude of sins.” 1 Peter 4:8 (NASB)