In "God's Word for Today" William Snider writes:
The Epistle to the Romans brings the explanation of the origins of sin and the forgiveness that is available through Christ. The presence of grace by which forgiveness is provided exceeds our comprehension. Some were saying that then perhaps the additional presence of sin brings more of this wonderful grace. Sin does not matter, because God will forgive anyway. In an interesting continuance of this logic, sin is a wonderful thing because sin gives the grace of God a continuing opportunity to operate. In short, sin brings grace. Paul recoiled in holy horror, “God forbid.” The thought was almost blasphemous. Paul argued from baptism that such a thought is totally inconsistent with the work of Christ in the heart of the believer. Baptism is a dividing line in the life of an individual. It marks a departure from the old life and an entrance into a new and different manner of living. Consequently, in a negative understanding, professing to live the new life while practicing the old life is a complete and total contradiction.
Source: Studies in Romans: Adult Teacher's Insights, page 28.