Matthew 23:8-12 NIV
“But you are not to be called ‘Rabbi,’ for you have one Teacher, and you are all brothers. And do not call anyone on earth ‘father,’ for you have one Father, and he is in heaven. Nor are you to be called instructors, for you have one Instructor, the Messiah. The greatest among you will be your servant. For those who exalt themselves will be humbled, and those who humble themselves will be exalted.
NIV: New International Version