The text suggests that at one time Paul saw the law as the only way God acts to reconcile humanity, but now that is no longer the case. He could no longer view Torah as the only window through which one could see God's justice at work. His new insight is the universal applicability of God's new way of righting wrong. The picture sketched here is not one that is narrowly applicable to one segment of humanity or to one geographical region. Its effects reach across the board of all humanity.
Faith is no longer a matter of ancestry or conversion to the Jewish way of life.
Jews are no longer privileged because of God's election of Israel and their role in salvation history. It is literally a gift available to every single person on earth. Here Paul insists that every one of us, regardless of our presumed status before God, misses the mark. To paraphrase v 23 a bit, we have continued to exchange God's glory for a flash in the pan. The universality of human guilt is the basis for the universality of grace.