In my simple thinking, it seems fairly straight forward. We are saved by grace through faith, not of works because we would boast. Getting "works" ahead of faith has troubled many a soul in meaningless religion, spiritual pride, anxious striving, depression, and fearfulness.
Yet shouting "legalism" anytime mention is made of sanctified living and good works is as grievous an error in my view -- the strident language itself seems to take on a "legalistic" tone as angry exchanges about theological purity and smug certainty pollute the very cause they espouse.
Paul simply asks, shall we continue in sin that grace may abound? I love how this flower just blooms for its Makers glory in the shadow of the Cross. Can there be any other response than fruitfulness to the great and complete sacrifice made there for you and me?
(Image taken in Itea, Greece -- Oct. 2011)