Romans 6:14

You are not under the law of Moses, as some of you were before: but now you are all under grace, or the law of grace, where you may find pardon for your sins. But take care not to abuse this grace of pardon offered you, nor multiply your sins, and defer your conversion, as some may do, by presuming, that after all, by the merits of Christ, you can find pardon. This, says Tertullian, is the greatest ingratitude, to continue wicked, because God is good. Reflect that you make yourselves servants of him whom you obey. By yielding to your passions, you become slaves to sin. If you keep your obedience to the law of Christ, and to his doctrines, the form of which you have delivered to you by the gospel, you are the happy servants of justice, and the servants of God, who is justice itself. (Witham)