Matthew 23:6-10

and they love the place of honor at feasts and the best seats in the synagogues and greetings in the marketplaces and being called rabbi by others. But you are not to be called rabbi, for you have one teacher, and you are all brothers. And call no man your father on earth, for you have one Father, who is in heaven. Neither be called instructors, for you have one instructor, the Christ.