Romans 6:19

ἀνθρώπινον λέγω διὰ τὴν ἀσθένειαν τῆς σαρκὸς ὑμῶν. Cf. Romans 3:5; Galatians 3:15. Paul apologises for using this human figure of the relation of slave to master to convey spiritual truths. But what is “the weakness of the flesh” which makes him have recourse to such figures? Weiss makes it moral. The Apostle speaks with this unmistakable plainness and emphasis because he is writing to morally weak persons whose nature and past life really made them liable to temptations to libertinism. This seems to me confirmed by the reference, which immediately follows, to the character of their pre-Christian life. Others make the weakness rather intellectual than ethical, as if Paul said: “I condescend to your want of spiritual intelligence in using such figures”. But this is not a natural meaning for “the weakness of your flesh,” and does not yield so good a connection with what follows. δοῦλα τῇ ἀκαθαρσίᾳ καὶ τῇ ἀνομίᾳ : ἀκαθαρσία defiling the sinner, ἀνομία disregarding the will of God. If εἰς τὴν ἀνομίαν should remain in the text, it may suggest that this bad life never gets beyond itself. On the other hand, to present the members as slaves to righteousness has ἁγιασμός in view, which is a higher thing. ἁγιασμὸς is sanctification, primarily as an act or process, eventually as a result. It is unreal to ask whether the process or the result is meant here: they have no meaning apart.