"Those who canvass for positions of honor are the ones who exalt themselves; those who delight in serving and caring for others are the ones who humble themselves so as to be exalted by God. Note that it is not those whom the Lord exalts who will be humbled, but those who exalt themselves, and similarly it is those who of their own accord humble themselves who will be exalted by the Lord.
"After specifically reserving the office of teaching to himself, Christ immediately went on to give as the rule of this teaching that whoever wants to be greatest should be the servant of all. And he gave the same rule in other words when he said: Learn of me, for I am meek and humble of heart. Anyone therefore who wants to be Christ's disciple must hasten to learn the lesson he professes to teach, for a perfect disciple will be like his master. Otherwise, if he refuses to learn the master's lesson, far from being a master himself, he will not even be a disciple."
Paschasius Radbertus (AD 785-860), On Matthew 10, 22: PL 120, 769-770