Luke 22:24-27 And there was also a strife among them, which of them should be accounted the greatest. And he said unto them, The kings of the Gentiles exercise lordship over them; and they that exercise authority upon them are called benefactors. But ye shall not be so: but he that is greatest among you, let him be as the younger; and he that is chief, as he that doth serve. For whether is greater, he that sitteth at meat, or he that serveth? is not he that sitteth at meat? but I am among you as he that serveth.
Matthew 20:28 Even as the Son of man came not to be ministered unto, but to minister, and to give his life a ransom for many.
John 13:12-17 So after he had washed their feet, and had taken his garments, and was set down again, he said unto them, Know ye what I have done to you? Ye call me Master and Lord: and ye say well; for so I am. If I then, your Lord and Master, have washed your feet; ye also ought to wash one another’s feet. For I have given you an example, that ye should do as I have done to you. Verily, verily, I say unto you, The servant is not greater than his lord; neither he that is sent greater than he that sent him. If ye know these things, happy are ye if ye do them.