Our Scripture reading today is Romans 6:12-14.
Verse 14, "For sin shall not have dominion over you: for ye are not under the law, but under grace."
Once we have turned to Jesus Christ by faith and received Him as our personal Saviour, we are free to live by the grace of God.  Our salvation and our daily living are only by God's grace.  Sin should no longer be dominating the child of God.  This verse could be considered a test of whether or not we are truly born again.  Does sin dominate your life?  
The born again Christian will not be free of sin, but sin will no longer continually prevail over us do to the victory that Jesus Christ provided on the cross.  Romans 8:37, "Nay, in all these things we are more than conquerors through him that loved us."  I really like this illustration that I read about Romans 6:14: "Once the caterpillar has been made a butterfly, the butterfly has no business crawling around on trees and leaves like a caterpillar again."  God's grace has changed us for His glory.  We have no reason to crawl back into a life of sin and defeat.