The Pharisees were, basically and initially, a group of the elite, educated society "muckity mucks", who took it upon themselves to keep all the Laws, so that when God looked down, He would not see all the Average Abes doing wrong and violating laws, and curse the nation of Israel. Supposedly, He would only see them doing right (and they DID do VERY right, and were good men, hoping to redeem their society) and would thus bless the country. The Pharisees were, initially, not really a "religious" group, per se, but just social leaders trying to advance the nation of Israel in God's eyes. Of course, like everything, power took over, and they assumed a religious leadership role in later years, and became quite corrupted..