JMNT(i)
18 For I have seen and thus know that good (or: virtue) is not habitually making its home (housing itself; dwelling; = living) within me – that is, within my flesh (= alienated self; or: = life under Torah) – for the [ability or condition] to will (or: intend; purpose) is continually lying near beside me, but the [ability, condition or circumstance] to constantly produce (work down, effect and accomplish) the ideal (the fine; the excellent; the beautiful) [is] not.
19 For that which I constantly intend (will; purpose) – a good thing (a noble deed; a virtuous act) – I do not normally do (or: I am not consistently doing what I continually will, intend and purpose: [something] good), but rather, that which I continuously do not intend (or: will) – a worthless (ugly; ignoble; base; bad; evil) thing – this I habitually put into practice!
20 Yet if that which I am not willing (intending), this I am constantly doing, I, myself, am no longer producing (working down and effecting) it, but rather, [it is] the Sin (the failure; the error; the missing of the Goal; the deviation [from Torah-keeping]) continuously housing herself (making its home; dwelling) within me [= Adam, or an Israelite, personified].
21 Consequently I keep on finding the principle (or: this law) in me – in the person normally willing (purposing; intending) to habitually do (perform; produce) the ideal (the beautiful; the fine) – that in me (or: with me; for me) the worthless (the ugly; the ignoble; the base; the evil) is constantly lying close by.