Romans 6:15

What then? shall we sin, because we are not under the law, but under grace? God forbid.

What then? shall we sin, [ hamarteesomen (G264)]. But this future tense, as in Romans 6:1, has hardly a vestige of support. The only authorized form here is the subjunctive [ - hamarteesoomen (G264)] - 'May we sin,' or (more idiomatically), 'Are we to sin' (see the note at Romans 6:1),

Because we are not under the law, but under grace? God forbid. The apostle here resumes the statement of Romans 6:1 under a somewhat new form, with the view of pressing home on believers the inconsistency and ingratitude of so acting, and in fact the certainty that they will not.