Mark 10

You can sense that even after several previous teachings of the Savior on the matter, there was still an attitude of pride, pecking order, or even who was more important to the Savior. There even seemed to be some dispute amongst the disciples to which -

"...Jesus called them to him, and saith unto them, Ye know that they which are accounted to rule over the Gentiles exercise lordship over them; and their great ones exercise authority upon them.
43 But so shall it not be among you: but whosoever will be great among you, shall be your minister:
44 And whosoever of you will be the chiefest, shall be servant of all." (New Testament | Mark 10:42 - 44)

To make the point, He continued -

"For even the Son of man came not to be ministered unto, but to minister, and to give his life a ransom for many." (New Testament | Mark 10:45)

Previously, the Lord had even rebuked Peter on the matter teaching -

"...there are many who make themselves first, that shall be last, and the last first." (New Testament:Mark 10:31)

Elder Bruce R. McConkie commented -

"In spite of the rebuke but shortly before given Peter, that "there are many who make themselves first, that shall be last, and the last first" (I. V. Mark 10:30); and in apparent open disregard of the teaching just given in the Parable of the Laborers in the Vineyard, that all servants worthy of exaltation would be rewarded alike, each receiving his "penny" appointed—James and John, aided by their mother, now entreat Jesus for a promise that they will rank next to him in his eternal kingdom.

Tolerant of their human weaknesses, for they as yet have not gained the full and glorious vision of the gospel, Jesus thereupon teaches them how greatness in God's kingdom is gained. It is not the position occupied, but the service rendered; not the office held, but the call magnified; not the rank enjoyed, but the labors performed; not the pre-eminent station attained, but the spiritual diligence exhibited; not where one sits with reference to the King, but the love and obedience shown forth to him. (DNTC 1:565.)