Matthew 23:8-12

But be not ye called Rabbi: for one is your Master, even Christ; and all ye are brethren. And call no man your father upon the earth: for one is your Father, which is in heaven. Neither be ye called masters: for one is your Master, even Christ. But he that is greatest among you shall be your servant. And whosoever shall exalt himself shall be abased; and he that shall humble himself shall be exalted.