Tertullian

“ What do the Galatians read? “Manifest are the works of the flesh.” What are these? Among the first he has set “fornication, impurity, lasciviousness:” “ (concerning) which I foretell you, as I have foretold, that whoever do such acts are not to attain by inheritance the kingdom of God.” [3] The Romans, moreover,—what learning is more impressed upon them than that there must be no dereliction of the Lord after believing? “What, then, say we? Do we persevere in sin, in order that grace may superabound? Far be it. We, who are dead to sin, how shall we live in it still? ”

“ For in that He died to sin, He died once for all; but in that He liveth, to God He liveth. Thus, too, repute ye yourselves dead indeed to sin, but living to God through Christ Jesus.” [4] Therefore, Christ being once for all dead, none who, subsequently to Christ, has died, can live again to sin, and especially to so heinous a sin. Else, if fornication and adultery may by possibility be anew admissible, Christ withal will be able anew to die. Moreover, the apostle is urgent in prohibiting “sin from reigning in our mortal body,” [5] whose “infirmity of the flesh” he knew. ”

“ For even if he has affirmed that “good dwelleth not in his flesh,” [6] yet (he means) according to “the law of the letter,” [7] in which he “was:” but according to “the law of the Spirit,” [8] to which he annexes us, he frees us from the “infirmity of the flesh.” “For the law,” he says, “of the Spirit of life hath manumitted thee from the law of sin and of death.” ”