The Doctor: A Help in Interpreting Romans 6

As we come to this detailed outworking of his argument by the Apostle it is essential that we should hold clearly in our minds what he is setting out to do.  He is refuting the charge brought against his teaching stated in the first verse, ‘Shall we continue in sin, that grace may abound?’  He is not giving an exposition of the way of holiness and of sanctification, as is commonly suggested; he is simply refuting the charge that is brought against the doctrine of justification by faith, and against the finality and certainty of our salvation in Christ.  – D. Martyn Lloyd-Jones, Romans Vol. 5, p. 42