Romans 6:1-5 - Christians should not live in sin

At the beginning of Romans chapter 6, Paul addresses Christians and how, now that they are converted, they need to forsake sin.

Look at these two verses together:

Romans 5:20 “Moreover the law entered, that the offence might abound. But where sin abounded, grace did much more abound:”

Romans 6:1 “What shall we say [...]