Contradiction with John 18:36
Jesus says His kingdom is not of this world, while Mark 5:21 presents Him interacting with this world.
John 18:36: Jesus answered, My kingdom is not of this world: if my kingdom were of this world, then would my servants fight, that I should not be delivered to the Jews: but now is my kingdom not from hence.
Contradiction with 1 Corinthians 1:27
God chooses the foolish things to confound the wise, yet Mark 5:21 describes Jesus drawing a crowd for His wisdom and miracles.
1 Corinthians 1:27: But God hath chosen the foolish things of the world to confound the wise; and God hath chosen the weak things of the world to confound the things which are mighty;
Contradiction with Matthew 19:30
Many that are first shall be last; last, first. In Mark 5:21, Jesus is the center of attention, seemingly contradicting this reversal principle.
Matthew 19:30: But many [that are] first shall be last; and the last [shall be] first.