More Luther:
Sect. 164.—I OMIT to bring forward that truly Achillean Scripture of mine, which the Diatribe proudly passes by untouched—I mean, that which Paul teaches, Rom. vii. and Gal. v.,
that there is in the saints, and in the godly, so powerful a warfare between the spirit and the flesh, that they cannot do what they would. From this warfare I argue thus:—If the nature of man be so evil, even in those who are born again of the Spirit, that it does not only not endeavour after good, but is even averse to, and militates against good, how should it endeavour after good in those who are not born again of the Spirit, and who are still in the "old man," and serve under Satan?
Nor does Paul there speak of the ’grosser affections’ only, (by means of which, as a common scape-gap, the Diatribe is accustomed to get out of the way of all the Scriptures,) but he enumerates among the works of the flesh heresy, idolatry, contentions, divisions, &c.; which he describes as reigning in those most exalted faculties; that is, in the reason and the will.
If therefore, flesh with these affections war against the Spirit in the saints, much more will it war against God in the ungodly, and in "Free-will." Hence, Rom. viii. 7, he calls it "enmity against God."—I should like, I say, to see this argument of mine overturned, and "Free-will" defended against it.
Martin Luther's The Bondage of the Will.