Romans 7:18

For I know that in me, that is, in my flesh, dwelleth no good thing: for to will is present with me, but to do that which is good is not.

Paul in this verse did not deny to man under the law of Moses any intention of doing right, for the power "to will" is allowed; only the ability to deliver on the good intention is denied. Here it is well to note some of the distinctions which theologians like to make when discussing such a thing as the will. Paul did not always use such terms in the sense of definitions accepted by people. Thus:

When Luther and Calvin deny a good will to man under the Law, they understand by it something entirely different from what is meant here.[20]

It is exactly in this, taking "will" to mean what Paul clearly did not mean, that the "converted Christian" is imported as the subject of this passage. It will be recalled from the statements Paul made in earlier chapters (Romans 2:14 etc.) that he did not deny a certain "good will" even to the reprobate Gentiles. Again from Brunner:

The Gentile as well as the atheist knows something of this delight in the good, this approval of the Law, even though he swears a thousand times that he does not believe in God. We are not here concerned with the atheist; but one thing is clear: Just as Paul does not entirely deny the Gentile the knowledge of the Law, so he also does not deny him a certain delight in the Law, a certain approval of it; in which case, the Gentile, of course, does not know whose law it is. Paul the Christian knows.[21]

Thus it is clear why Paul used language in referring to people under the Law that seems to have an application to Christians, especially when it is considered that there is a conflict (though nothing like that outlined here) in the heart even of Christians, this latter conflict being in the background of Paul's thought here, but certainly not the topic of his argument.

[20] Ibid., p. 65.

[21] Ibid.