Bart D. Ehrman, Peter, Paul and Mary Magdalene: The Followers of Jesus in History and Legend:
One thing that can be said about Pharisees is that the most common stereotype about them is almost certainly wrong. In the dictionary, today, if you look up the word Pharisee you’ll find as one of the later definitions “hypocrite.” This has always struck me as bizarre — somewhat like defining Episcopalian as “drunkard” or Baptist as “adulterer.” To be sure, there are no doubt Episcopalian alcoholics and Baptist philanderers, just as there must have been Pharisaic hypocrites. But as I tell my students, agreeing to commit hypocrisy was not an entrance requirement for the Pharisaic party. There was no hypocritic oath.
One thing we do know about the Pharisees is that they strove to follow God’s law as rigorously as they could. This doesn’t make them hypocrites; it makes them religious. (p. 106)
It seems the cultural equation Pharisee = hypocrite must come from Matthew 23, where Matthew’s Jesus juxtaposes the terms 7 times within 17 lines (13, 14,15, 23, 25, 27, 29). Outside Matthew, the words appear together only once (Luke 11:44), again on Jesus’s lips.
Matthew’s is the most insistently Jewish of the gospels, not just Jewish, but rabbinic Jewish, i.e., Pharisaic. It is also, some have argued, the most anti-Jewish (though I think there are passages in John that might outstrip Matthew for vitriol).
When I was in college, the most venomous attacks I’d hear against black men came from the mouths of black women. If I quoted them to you out of context, you’d take it as racist “hate speech.” The context makes all the difference. I think Christianity becoming a gentile religion ended up taking a lot of this ancient Jewish infighting very much out of context.