Romans as was mentioned is the key. The law exist to show a sinner they need a savior. We we are born again we are taken out from being under the law and then placed under grace. This does not let want live a life free to sin. It just means we do not have worry every time we sin that God's love stops. We because of grace have a way to be cleansed and that is repentance (1 John 1:9). Now one who lives a life of blatant and willful sin is NOT a born again believer (1 John chapter 2). So rules and laws are not important as knowing Jesus as Savior. When you do you will not want to willfully sin.