How did the Pharisees view themselves?
The Pharisees viewed themselves as righteous in their own eyes. They considered themselves righteous, especially the most religious Jew, and were enraged when told that no one is righteous, not even them. They were so offended they could have put the speaker to death.
Les explains that for almost 2000 years the Jewish community had been taught they were special, God's covenant people, set apart from the rest of the world, not to intermarry and to stay within their tribes. So when the Apostle declared there is no difference between Jew and Gentile, it infuriated them. They followed him from city to city, trying to defeat him, and plagued him until his death. The Pharisees were righteous in their own eyes, so hearing 'there is none righteous, no not one' made them want to put him to death. They did not accept that even the most religious Jew is not righteous.