A Pharisee is not someone who is a mere legalist, who concerns himself with too much religion. A Pharisee is one who is a legalist in trivial matters and an antinomian in central matters. He is concerned too much about the small things and too little about the big things. Jesus would have us be concerned about all things.
“But woe to you Pharisees! For you pay tithe of mint and rue and every kind of garden herb, and yet disregard justice and the love of God; but these are the things you should have done without neglecting the others.” Luke 11:42