John Newton and Doug Wilson

Newton-
"And I am afraid there are Calvinists, who, while they account it a proof of their humility that they are willing in words to debase the creature, and to give all the glory of salvation to the LORD, yet know not what manner of spirit they are of. Whatever it be that makes us trust in ourselves that we are comparatively wise or good, so as to treat those with contempt who do not subscribe to our doctrines, or follow our party, is a proof and fruit of a self-righteous spirit. Self-righteousness can feed upon doctrines, as well as upon works; and a man may have the heart of a Pharisee, while his head is stored with orthodox notions of the unworthiness of the creature and the riches of free grace."

Wilson-
"The Pharisee who went down to the Temple to pray actually began his prayer with one of the solas-Soli Deo Gloria. 'I thank Thee, God...' Perfectly orthodox. And he went home unjustified to boot."