“The parable, in Luke 18:9-14, was directed against those who thought they were righteous and looked down on everyone else. We need to place due emphasis on the phrase ‘who thought they were righteous.’ People who preen themselves on their own righteousness go home unjustified even if they were baptized in a joint service with the pope and Billy Graham officiating. The self-righteous can trust in anything but Christ. Those who have the rightousness of Christ can trust in anything but themselves. Which means they are trusting in Christ alone.
This should not be a complicated problem. It seems to me that many of our difficulties with this are because we do not want to acknowledge that there are two on-going categories among the sanctified—the sanctified and the unsanctified. Among the justified we find the same division—the justified and the unjustified. Among the baptized elect we find the elect and the non-elect. And this is not the creed of some kind of Zen Reformation. It is basic to all spiritual wisdom. Among all the descendents of Sarah, we find descendents of both Sarah and Hagar. And this is why the church today, all sons of Isaac, contains so many Ishmaelites.”
Douglas Wilson. A Pauline Take on the New Perspective. Credenda/Agenda. Vol. 15. Iss. 5. 14-15.