"What shall we say then? Shall we continue in sin, that grace may abound?"

Grace doesn't make us careless about sin. When we gave our lives over to Christ as Lord, we stopped being sinful. We don't want sin or its power to be in charge of our lives. We don't want to forget how much Jesus had to suffer to pay for our sins. Paul says things as strongly as he can ("By no means!" is a much too mild translation: "God forbid!" "Impossible to imagine!" or "Horrible!" would be much better). As people who have been saved by God's grace, we know that sin is more than just breaking a rule. Sin is putting Jesus' love for us in a bad light by choosing our sin over what He did for us. Sin is turning our backs on the Father, who paid so much to bring us into His family. Sin hurts our Father because it shows that we love sin more than we love Him. Lastly, sin is when we choose to do what we want instead of what God wants. This choice leads to self-destruction.