Use the adjective pharisaic to describe a religious person who is smug and judgmental, especially if his actions prove that he's much less holy than he pretends to be.
Someone who exaggerates how morally upright or pious she is can be called pharisaic. Another way to say it is "holier-than-thou." Pharisaic people tend to talk a lot about how devout and religious they are, but their actions don't quite measure up to their words. The word pharisaic has its roots in the Greek Pharisaios, which in turn comes from an Aramaic word, perishayya, or "separate." In the history of Judaism, the Pharisees were an important school of religious thought.