Passage
Let not then the sin reign in your mortal body, to obey it in its desires;
Let not then the sin reign in your mortal body, to obey it in its desires;
Romans 6:10 for in that he died, to the sin he died once, and in that he liveth, he liveth to God;
Romans 6:11 so also ye, reckon yourselves to be dead indeed to the sin, and living to God in Jesus Christ our Lord.
Romans 6:12 Let not then the sin reign in your mortal body, to obey it in its desires;
Romans 6:13 neither present ye your members instruments of unrighteousness to the sin, but present yourselves to God as living out of the dead, and your members instruments of righteousness to God;
Romans 6:14 for sin over you shall not have lordship, for ye are not under law, but under grace.
The verse centers on "reign", "mortal", "body", "obey", and "desires". It is saying that the verse draws attention to "reign" and "mortal", so its meaning should be read from those terms before moving to application.
The nearby context moves from verse 11's "so also ye reckon yourselves to be..." into verse 13's "neither present ye your members instruments of...", so "reign" and "mortal" belong inside that flow. In Romans context, the local focus is righteousness by faith, union with Christ, life in the Spirit, and God's covenant faithfulness.
A plain takeaway is to answer the verse's own emphasis on "reign" and "mortal" with trust shaped by these words, not by a vague optimism outside the passage.