Sometimes sin is described in Scripture as a rebellion, a terrible insurrection, a rising up against God. But sometimes it is not that. Sometimes "sin is merely banal and ugly and loathsome", having nothing of that human (and damnable) pride and self-confidence, but only the failure to act, only the resolute determination to be nothing and do nothing. "The sinner is not merely Prometheus or Lucifer. He is also - and for the sake of clarity and to match the grossness of the matter, we will use rather popular expressions - a lazy-bones, a sluggard, a good-for-nothing, a slow-coach and a loafer" (CD IV/2).
Because the Gospel not only liberates us from our action - our desperate attempts to make something of ourselves - by telling us that all is done in Christ, it also liberates us from our inaction - our no less desperate attempts to evade responsibility and action - by telling us that we can proceed on the secure basis of the righteousness of Christ. The good news of Jesus is that in him we are really new people, who do not need to work to make ourselves something, but are already made something and therefore can (and must) work. Our sinful self with its sinful actions is put to death, but we are not left as a vacuum. Rather, we are created in Christ Jesus for good works.
So, no more inaction through despair - our work is not good enough, but it is ordained and blessed. And no more inaction through laziness - our work is necessary because it is ordained and blessed.
When Christ calls a man, he bids him come and live!