One of my favourite sermons of Martin Luther-King Jr is his 'Drum Major instinct sermon. it makes the hair stand up on the back of my neck. If you can, look up the whole text of the sermon, and even better listen to the mp3. Here is an excerpt.
"...I want you to see what Jesus was really saying. What was the answer that Jesus gave these men? It's very interesting. One would have thought that Jesus would have condemned them. One would have thought that Jesus would have said, "You are out of your place. You are selfish. Why would you raise such a question?"
But that isn't what Jesus did; he did something altogether different. He said in substance, "Oh, I see, you want to be first. You want to be great. You want to be important. You want to be significant. Well, you ought to be. If you're going to be my disciple, you must be." But he reordered priorities. And he said, "Yes, don't give up this instinct. It's a good instinct if you use it right. (Yes) It's a good instinct if you don't distort it and pervert it. Don't give it up. Keep feeling the need for being important. Keep feeling the need for being first. But I want you to be first in love. (Amen) I want you to be first in moral excellence. I want you to be first in generosity. That is what I want you to do."
And he transformed the situation by giving a new definition of greatness. And you know how he said it? He said, "Now brethren, I can't give you greatness. And really, I can't make you first." This is what Jesus said to James and John. "You must earn it. True greatness comes not by favoritism, but by fitness. And the right hand and the left are not mine to give, they belong to those who are prepared." (Amen)
And so Jesus gave us a new norm of greatness. If you want to be important—wonderful. If you want to be recognized—wonderful. If you want to be great—wonderful. But recognize that he who is greatest among you shall be your servant. (Amen) That's a new definition of greatness.
And this morning, the thing that I like about it: by giving that definition of greatness, it means that everybody can be great, (Everybody) because everybody can serve. (Amen) You don't have to have a college degree to serve. (All right) You don't have to make your subject and your verb agree to serve. You don't have to know about Plato and Aristotle to serve. You don't have to know Einstein's theory of relativity to serve. You don't have to know the second theory of thermodynamics in physics to serve. (Amen) You only need a heart full of grace, (Yes, sir, Amen) a soul generated by love. (Yes) And you can be that servant."
For full text: https://kinginstitute.stanford.edu/king-papers/documents/drum-major-instinct-sermon-delivered-ebenezer-baptist-church
for a good listen