We are made righteous by faith in Jesus Christ, and we access the grace that we need by faith in Him (Rom 5).  The fact that we have abundant grace does not give us an excuse or license to sin (Rom 6).  We cannot overcome the works of our flesh in our own strength (Rom 7).  We are victorious in every situation if we walk in the Spirit (Rom 8).  Study these chapters and watch God change things.  Be encouraged!