There is a sense in which the doctrine of justification by faith only is a very dangerous doctrine; dangerous, I mean, in the sense that it can be misunderstood. It exposes a man to this particular charge. People listening to it may say, ‘Ah, there isa  man who does not encourage us to live a good life, he seems to say that there is no value inner works, he says that “all our righteousnesses are as filthy rags.” Therefore what he is saying is, that it does not matter what you do, sin as much as you like.’ There is thus clearly a sense in which the message of ‘justification by faith only’ can be dangerous, and likewise with the message that salvation is entirely of grace. I say therefore that if our preaching does not expose us to that charge and to that misunderstanding it is because we are not really preaching the gospel.

Martin Lloyd-Jones, Romans 6, The New Man (Sermon One, Romans 6:1,2), p. 9. But it is precisely that “misunderstanding” which leads to the question and answer of Romans 6:1-2 “What shall we say then? Shall we continue in sin that grace may abound? God forbid. How shall we that are dead in sin live any longer in it.”

What is the business of grace? Is it to allow us to continue in sin? No! It is to deliver us from the bondage and the reign of sin, and to put us under the reign of grace. So when a man asks, “Shall we therefore continue in sin that grace may abound?” hr id merely showing that he has failed to understand either the tyranny or the reign of sin, or the whole object and purpose of grace and its marvelous reign over those who are saved.