Romans 7:17-18

17So now [if that is the case, then] it is no longer I who do it [the disobedient thing which I despise], but the sin [nature] which lives in me.

18For I know that nothing good lives in me, that is, in my flesh [my human nature, my worldliness—my sinful capacity]. For the willingness [to do good] is present in me, but the doing of good is not.