Contradiction with Matthew 5:5
Mark 9:34 involves a discussion among disciples about who is the greatest, but Matthew 5:5 teaches that the meek, not those seeking greatness, will inherit the earth.
Matthew 5:5: Blessed [are] the meek: for they shall inherit the earth.
Contradiction with Matthew 20:26-27
While in Mark 9:34 disciples argue about being greatest, Matthew 20:26-27 emphasizes that whoever wants to be great must be a servant, contrasting self-promotion.
Matthew 20:26-27: But it shall not be so among you: but whosoever will be great among you, let him be your minister;
Contradiction with Philippians 2:3
Mark 9:34 shows disciples arguing greatness; Philippians 2:3 urges believers to do nothing from selfish ambition, contradicting their behavior.
Philippians 2:3: [Let] nothing [be done] through strife or vainglory; but in lowliness of mind let each esteem other better than themselves.
Contradiction with Luke 22:26
In contrast to the disciples' argument in Mark 9:34 about greatness, Luke 22:26 instructs that the greatest should become like the youngest and the leader as one who serves.
Luke 22:26: 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.
Contradiction with James 4:10
Mark 9:34 discusses seeking to be greatest, whereas James 4:10 counsels humility so one may be exalted by the Lord, a contradiction in approach to greatness.
James 4:10: Humble yourselves in the sight of the Lord, and he shall lift you up.