Christians Against Christians: Already In the New Testament

Ive long been intrigued by the fact I think its a fact that the people we get in the BIGGEST fights with are those closest to us: spouses, siblings, parents, good friends.  Sometimes we fight with others, of course.  But its those closest to us that really seem to annoy us.  Which of us has not had situations get completely out of hand?

That has made some people wonder about the New Testament.  For example, Jesus main opponents during his ministry are with the Pharisees.  Is that because he...