Romans 6:12 - Coke's Commentary on the Holy Bible

Let not sin therefore reign in your mortal body— Sin is here spoken of as a person; a prosopopoeia made use of throughout this and the following chapter; which must be observed if we will understand them right. See 1 Peter 4:1. Dr. Heylin renders this verse, Let not sin therefore reign in your mortal bodies, so as to obey it by indulging the appetites of the body. Mr. Locke observes, that the preposition εν, in the Apostle's writings, often signifies by; and as here, as well as in the following chapter, Romans 7:18; Romans 7:24 and elsewhere, he places the root of sin in the body, the sense seems to be, "Let not sin reign over you, by the lusts of your mortal body." The force of St. Paul's argument appears to be this: "By your baptism you are engaged to become conformable to Christ's death and resurrection: he once died for sin, so do you count yourselves dead to sin: he rose to life, wherein he lives wholly to God; so must your new life be under the vassalage of sin no more; but you must live entirely to the service of God, to whom you are devoted."