What then? Shall we sin because we are not under the law but under grace? By no means! Don’t you know that when you offer yourselves to someone as obedient slaves, you are slaves of the one you obey—whether you are slaves to sin, which leads to death, or to obedience, which leads to righteousness? But thanks be to God that, though you used to be slaves to sin, you have come to obey from your heart the pattern of teaching that has now claimed your allegiance. You have been set free from sin and have become slaves to righteousness.
Romans 6:15-18 (NIV)